Cheryl is round at mine for the next installment of the Matt Rogham direct messaging experiment. To be honest, it's probably the fiftieth installment by now (I've lost track) because I've been keeping up direct messages with him when I'm on my own.

I feel as if I know him well by now, Matt. He differs from the person you read about in the trashy magazines. Different, how? Well, it is as if the person in the magazines is this cool dude. There are always a lot of photos of him in the trashy magazines—pictures of him with his celebrity mates, hanging out at parties, coming out of nightclubs or on the red carpet. 

The magazines also like to use pictures of him topless. There is a lot of them too, and there are quite a few snaps and stories where he is working out. He always seems to be lifting heavy weights or sweating buckets, getting in training for that film role he told Cheryl about.

But the guy on Instagram and Twitter? Not so much. The coolness melts away. His posts to his millions of followers are okay—dull, and a bit "come and see my latest movie y'all", and there are always shed-loads of selfies and work-out pics—but the direct messages are something else entirely. 

He's a bit... it took me a while to work out what I thought because you don't expect it from someone as rich and famous, but Matt Rogham's clingy. Sometimes he comes out with this super confident stuff. "Hey Cheryl we should hang out. You'd love it," statements to this girl he met online only a few weeks ago. Other times he asks me (I mean Cheryl) what I think of him. In my opinion, is he's losing muscle tone, or did I catch him in such-and-such a movie, and was he much better than anyone else in that film or was he shit?

I've (I mean Cheryl) almost been counselling him. And another thing—his spelling is atrocious. If asked, I'd say his agent does his general posts, and he's allowed to do his own direct messages. 

Whatever. That makes me Cheryl's agent, I suppose. My client, at this moment in time, is on my bed, feet up (shoes and all, even though I tutted as she did it) and reading the latest copy of heat magazine. 

"She's got fat, hasn't she?" she asks as I send Matt messages and keep an eye on Cheryl's various accounts. She thrusts the magazine at me, showing me the picture of Vanda Hoffingham, Matt Rogham's ex. The picture is blurry, and she's wearing a baggy t-shirt, no make-up and denim shorts. As she is usually Hollywood skinny, I can see what Cheryl means. 

"Yeah," I say, and hate myself for it. A few months ago, I found an interview online with Vanda Hoffingham and she said she had battled an eating disorder as a teenager, and what a difficult thing it was to admit. When I read the interview, I stretched out my fingers to touch her face on the screen. Do you know what I go through, Vanda? 

"It still troubles me from time to time," she said. "And it's the big taboo. It affects so many people in this business, but not many of us are prepared to admit it. We are all expected to look a particular way—even if all you're playing is supposed be a cop. You know, someone who doesn't need to look amazing."

I clear my throat and try again. "She's not that fat," I tell Cheryl. "She just looks normal in that pic."

Cheryl takes back the magazine and snorts. "Yeah, but still fatter than she should be, I mean, check this out." She pulls out her phone and finds a picture online of Vanda a few months ago, and the difference is noticeable in her face and hips.

The magazine article calls her curvy, the reporter crowing that Vanda looks a little more "curvy than normal". We all know what that means in magazine terms. And it's an added bonus that heat managed to find a photo of her wearing no make-up. In it, she is softer and younger.

My thoughts never stray too far from food. I start imagining what Vanda might have been eating to get 'curvy'. They've got lots of food in America, after all. Maybe she's been stuffing her face with donuts, or tucking into pancakes and maple syrup. Then there are those giant-size portions you can get in restaurants, the ones Man Vs Food likes to go to. Poor Vanda. Imagine being surrounded by all that food and not being able to eat it most of the time because you need to stay skinny.

Cheryl takes out a lipstick from her bag and applies it, along with some bronzer, the excess dusty glitter of it dropping on my bed cover, and a bit more eyeliner. She yanks out her shirt, un-dos the top two buttons of it and ties it under her bust so that her skinny stomach is on show. She gets off the bed and starts to rummage through the chest of drawers at the back of the room.

"Hey, what are you looking for?" I'm glad I don't use the drawers to stash my secret sweetie supplies.

"Found 'em!" she says, her voice triumphant, and stands up holding a pair of old black denim cut-offs of mine. She starts wiggling out of her own jeans and into the cut-offs.

"They won't fit you," I start to say and then trail off when I realise that they do actually fit Cheryl. She has to pull them in at the waist, but the material clings to her bottom and the top of her thighs.

A quick hair ruffle and she thrusts her phone at me. "Take my pic!" 

I shrug and hold the phone in front of her, clicking a few times and changing the angle so that I can get the best shot. I take 28 pictures altogether and we spend some time working out which one is the best. Then we run the final choice through a few filters, to find what lighting is the most flattering, and doing the whiter teeth, whiter eyes thing. 

The end result is amazing—so good Cheryl decides to make it her phone wallpaper.

"Stick it on Instagram and Twitter," she says, "Matt can see the difference between me in a pair of shorts and Vanda."

"@mattrogham4real just a little treat for you for the weekend."

I don't make it a direct message. Doesn't the public deserves to see Cheryl at her finest, and I'm proud of my photography stroke editing skills. A year ago I couldn't take a decent picture if my life depended on it. In the last few months, I've taken so many of Cheryl and tried all the editing software I'm now a pro.

Seconds later, Matt sends a message right back. "@chezza2002 sweeeeet and SOOOO hot". He must have control over his own account at the moment.

Minutes later, as you might expect, Cheryl has added another few hundred people to her followers, including heat magazine and another of the trashy's we like to read, Starz. 

"God, that's amazing!" Cheryl says, with a grin at me. "Flippin' awesome an' all. Do you think heat or PopSugar will phone me up and ask me if I'm Matt Rogham's new mystery girlfriend?"

"They'd need your phone number first," I point out. I'm the brains behind this operation. "More likely, they'll send you a direct message and try to contact you that way. There'll be this story in the mag next week–" 

I pretend to be holding a microphone and I put on a fake American accent that wouldn't fool anyone.

"Just WHO is Matt Rogham's new girlfriend? Mystery girl Cheryl Acker appears to be the subject of the Hollywood star's affections as he has been Tweeting and commenting on her Instagram account all the time. Matt, recently split from celebrity girlfriend Vanda Hoffingham, has described Cheryl as the most beautiful girl on Twitter, though sources have said he has had to visit a specialist clinic because of the ra–"

Cheryl shrieks in outrage. "Stop that! I don't have any rashes. Be good, though, wouldn't it if the magazines wanted to interview me? Where would we do the interview though?" she glances at my bedroom. I live in a bigger house than Cheryl and my bedroom is double the size of hers. I've got this kind of Hollywood-looking bed too, with huge fluffy cushions and satin bed covers, and it's a hell of a lot tidier. 

Cheryl is probably imagining herself wearing nothing but a pair of high heels, hands strategically placed over her boobs and fu-fu and leaning back on those cushions. 

Her phone suddenly explodes, beeping like mad.

"Oh hey—wait a minute!" she yells and sits down with a thump on my bed, staring at her phone.

The smug grin has vanished and I snatch the phone off her. A whole lot of comments have come in. I only glance at a few of them, but they are all along the same lines.

"@chezza2002 cheap slapper"

"@chezza2002 who is this nobody? Vanda Huffington is much more beautiful."

"@chezza2002 did you break Matt & Vanda up, u hoor."

"@chezza2002 put ur fat stomach away, u dog."

I drop the thing as if it's burning hot. On the floor, it moves by itself, turning a centimetre or so either side vibrating as the notifications keep coming in.

Cheryl starts to cry, tears sliding over high cheekbones and dripping onto her chest. She bends over and picks up the phone. Her hands shake as she begins to type something in. I grab it off her again.

"Don't Cheryl, let me have a little think and then I'll put in something smart. We'll get our revenge, I promise."

I'm as shaken as she is. After all, it is me that's been doing all the updates for her so it feels as if these people are insulting me as well as her. But you need a smart reply, I remind her, one that will make Matt Rogham love you even more.

Then Matt wades in himself. "@chezza2002 – rise above it huney, remember how gorjuss and spesh U are X."

Wow, bad spelling apart, you couldn't ask for more.

"Thanx 4 all comments," I begin typing, "really appreciate people taking the time to message me. XX"

For good measure, I add in a pic I've got of Cheryl beaming at the camera. Cheryl stares at me. "That's what you're going to post? Because I soddin' well don't appreciate it."

"Nah," I say, "you've got to kill them with kindness. See, you get to seem like a nice person, and they all get to look like mad, mean trolls."

She relents when she sees the floods of messages she gets after I've posted it—mostly variations of 'you go girl' and 'rise above it like Matt says', 'u sound like such a nice person'. Etcetera. 

They stop her crying at least. "Why would people say such shit?" she asks me, and I say jealousy, nastiness, or perhaps someone who's having a terrible day. Post-binge, I could be one of them, crafting nasty words and horrible sentences because they take me out of myself for a few seconds. 

I don't. I promise, however tempting it is. And I don't remind Cheryl that in the last couple of months, she's made plenty of comments about certain reality stars. She joins in with those mad threads that start up from time to time, where someone gets slagged off and it goes on for ages before the trolls forget and move on to the next person.

"Downside of fame, Cheryl," I say like I'm all worldly-wise. But those comments rattled me too. I had to stop reading quickly. 'U hoor' and 'fat dog' weren't the worst of them. I even looked over my shoulder a couple of times. Suddenly, Cheryl and I weren't all by ourselves shut up in and the back of neck prickled as if a crowd thundered up the stairs coming to get us. People with baseball bats and guns, who were about to burst into the room in a second and start hitting us.

There were more nice remarks—'u sound like a lovely person', but they aren't the ones that stay in your head, are they? The messages Cheryl didn't see included. "We're coming to get you you fucking slag. DIE."

And those words weren't even meant for me.

Cheryl puts her phone away, and I put my laptop to sleep. "Shall we go out?" I say, hoping she'll say no.

"Nah," she says, "I'm good to go. I've gotta get home." She gets off my bed and changes back into her own clothes.

I'm relieved. My emergency stock of food beckons, and I've just heard Mum and Ben go out, which means I have the house all to myself. 

I wave goodbye to Cheryl from my window, and I see that she's taken her phone out of her pocket again—unable to resist. I wait till she's out of sight, a list of things running through my brain.

Large bar fruit and nut chocolate? Check.

Big bag Kettle chips (mature cheddar and red onion flavour)? Check.

Great British Baker Victoria sponge? Check.

Chunky monkey ice cream? Check.

I'm all set then. My heart beats furiously, still imagining those crowds of people and their weapons thundering up the stairs. I want rid of them, I want distraction, and for thirty minutes I want there to be nothing in my head except except food, food, food. 

I add to the checklist the new essentials. Tomato soup? Check. Pint glass? Check. Salt? Check. All is well.