A/N: This is a insanely late author's note, yet much overdo. Fist things first. I DO NOT OWN THE "THE PERKS OF HAVING A GIANT BOYFRIEND" SERIES! That lovely series belongs the one of my favourite authors, MastarHG over on AO3! This is now technically part 4-b because he already wrote a part 4. And before anyone asks, yes I did ask him, check out his tumblr http://septiplier-superstar.tumblr.com/ for clarification. Any who, onwards to the most smut I think I've ever posted! (Side note, yes I am into G/t Deal wid it!)

Nothing Ventured, Nothing Gained

AKA TPoHaGB pt 4

About a week has passed since Jack's newest growth spurt, and he had to get his house remodeled to accompany his new found gigantism, and Mark had to take up sewing lessons just to get Jack clothed but he didn't mind, it gave him something to do. Jack's growth had tapered off at 12' 2" (twelve feet and two inches just for those who don't know) and made doors a challenge even after the remodeling.

Jack had been recording a new episode of unravel, despite having to constantly readjust his setup, when he heard a noise coming from his room. He paused his game and recording and went to go check it out.

"Mark? You okay in there?" Jack asked through the door.

"Not really. I think I need an adult." Mark replied.

"What are ya talking about you are an adult. I should be able to leave you on your own for a bit without having to wor...ry." Jack said as he opened the door. What he saw had his massive jaw hanging and his dick lurching. Marks clothes had grown severely big on him, bigger than usual. "Mark? What happened?" Jack asked jaw still ajar.

"I honestly don't know. First thing I know I'm taking a nap, then when I wake up my clothes are like blankets on me!" Mark said voice slightly higher than usual, either from fear or shrinking. "I can honestly say this is the second strangest thing to happen to me this year." Mark said with a dopey grin on his face.

"What was the weirdest?" Jack asked, head cocked to the side.

"Getting covered in my giant boyfriend's baby making goo."  Jack had to admit that was highly unusual.

"Let's measure you to see just how small you've gotten." Jack suggested looking around for a tape measure. He had to admit Mark look really cute with his clothing being so big on him. "Found it!" Jack exclaimed. He lined up the tape and read aloud. "You are... 4' 6". I gotta admit I thought you were smaller." Jack said blushing slightly.

Mark frowned when he heard the measurements but then a couple of ideas came to his mind and brought his smile back tenfold.

"Hey Jack? There something I wanna try and I was wondering if you'd help me." Mark asked. He leaned up to Jack's face, in which Jack had to bend down to achieve, and whispered something in his ear.

"I don't see why not, but are you sure it's safe?" Jack asked his much smaller boyfriend. Mark just nodded assuringly.

Jack and Mark moved onto the bed, and got comfy. Mark rolled a condom on his dick (cause you mustn't be silly so wrap your willie) and got on Jack's thighs. He positioned his dick right up to Jack's piss slit and starting shoving his dick in.

"Oh my gawd!" They screamed out in unison. Mark started pumping faster while Jack stroked himself. Though neither member noticed Jack was getting ever slightly bigger. (more than just height if you catch my drift) The growth started picking up in speed, and millimetres became centimetres which became Inches. Jack was nearing the 15' mark before the two noticed.

"Jack are you getting even bigger?!" Mark asked in both shock and awe. Jack looked down at Mark and shrugged grabbed the tape measure and tried to take his measurements, emphasis on tried. The 13' long yellow rope didn't even reach his feet.

"Well than. I don't know how to react to this... forgive me for sounding pathetic, but um, you wanna ignore this for now and get back to what we were doing." Jack asked meekly

"You really are pathetic. Alright but if you start outgrowing the room then we're stopping." Inside Mark kinda did hope that Jack outgrew the room, but until then he had sounding to do.

Mark got into position again and reinserted himself, only to notice the hole was a lot looser than just a minute ago. Mark shrugged it off and went back into a rhythm.

It was defiantly getting bigger mark could fit his entire head in there if he really wanted to, and honestly he kinda did.

"Jack I wanna try fitting my head in your cock." The much smaller man said bluntly. "That is to say if you're okay with it." He said blushing.

"Will it hurt? Aw what the hell why not." Jack said.

Mark steeled himself for what he was about to do, but first he scooped up a lot of the pre seeping from Jack's dick and coated himself in it. Mark did a little sign of prayer the shoved his head in.

"Holy balls! This is intense!" Jack moan-screamed. As Jack yelled, Mark could feel his strong voice reverberating through his whole body.

"Prepare yourself, because I'm going deeper!" Jack had just barely heard Mark say. With that Mark started shoving his shoulders into Jack's beanstalk of a dick. Mark felt as the wall grew around him, Jack's dick was growing with him inside it. Mark took no time in getting the rest of his body in.

"Fuck Mark! I can't hold out much longer." Jack's voiced echoed around Mark.

"Let me have it big guy!" Mark shouted back. Mark saw torrents of white gushing forth from Jack's balls, in which he had loved so much, and it blew Mark clean on to the wall. Jet after jet hit him as he lay there, stuck to the wall. "It's official, we are doing this again tomorrow." Mark said sliding down from the wall.

"But first I need to clean you up." Jack said crawling towards him. "I always did wonder what my own cum tasted like." Jack chimed before licking Mark clean of his cum. As Jack licked, Mark came hard onto his tongue. "Now, if you can excuse me I'm in the middle of a very intricate puzzle game." Jack said before thumping off to his recording room. And that was only one of the perks of having a giant boyfriend Mark thought to himself. One of the many perks indeed.