During them kissing Lucifer started unbuckling and undoing his pants and did the same with Mephisto's pants. After this he pulled both of their dick's out and pressed them together and then started rubbing together up and down with his one of his hands.

Mephisto quickly gasp and rested his forehead on Lucifer's shoulder breathing heavily trying hard not to start moaning from this. He also then said seeming a bit annoyed.

Mephisto : is this.... really such a good idea to do in a public place...."

Lucifer : what do you think goes on here afterhours? '

Mephisto : you....you have a point...."

Lucifer : how long is your break?"

Mephisto :....an hour...."

Lucifer : heh...that's more than enough time for us "

Mephisto : .....did you the lock three door...."

Lucifer : yes I did"

Mephisto : good....you plan this didn't you?...."

Lucifer : I just wanted to talk but this is fine to"

Lucifer then start kissing his neck which made Mephisto want to bite him.

But as he was about to he immediately stop himself and just let Lucifer continue to kiss his neck.

Anyway as Lucifer was still rubbing their dick's together he suddenly stop and said.

Lucifer : let's try something else"

Mephisto : f...fine....I already know what your thinking"

Lucifer : good"

Mephisto then stood up and fully took his pants off. And then  got back on Lucifer's lap 
Like he was before. But this time was standing up on his knees getting ready to go down on Lucifer.

Anyway he then slowly started going down on Lucifer's dick  feeling it go inside of him after it was in. he started going up and down on it and then during this Lucifer started rubbing Mephisto's dick. all this pleasure he was feeling started to make him moan even moaning Lucifer's name.

After a few minutes Lucifer came inside of Mephisto and Mephisto came in Lucifer's hand.

And to Mephisto's shock he saw Lucifer lick his cum off his hand

Mephisto : what are you doing!?"

Lucifer : you can taste me. But I can't taste you?"

Mephisto got flustered again and then got off of lucfer's dick and sat back down on his lap and rested against Lucifer feeling tired.

Later Lucifer was laying down in the booth with Mephisto laying on top of him awake but resting. Lucifer's coat was also on top of Mephisto covering the bottom part of him since he didn't put his pants back on yet.

He wasn't sure what to think now about his relationship with Lucifer. It was confusing and messy.

Mephisto : .....is this what we're going to keep doing..... just screw each other whenever we feel like it?"

Lucifer : that's not why I do it"

Mephisto : what?"

Lucifer : .....I showed up here because I was worried about you. Because i-!?

Suddenly the Door and immediately closed right after in less than a second and him and Mephisto froze in horror at what just happened.

Mephisto : ......that was Diavolo..... forgot he was coming by later....."

Lucifer : ......"

Lucifer knew his fate was sealed and there was nothing he could do about it.

Meanwhile later at the castle Barbatos went to check on Diavolo in his office and found him sitting at his desk face down on the table mumbling to himself or something.

Barbatos: are you alright?"

Diavolo : no....can you erase my memory of the last 24 hours?"

Barbatos : what happened?"

Diavolo : I don't want to talk about it....."

Barbatos : weren't you going to see Mephisto?"

Diavolo : yeah...."

Barbatos : did you?'

Diavolo : ....I saw him....with Lucifer....."

Barbatos : oh t-Oh...."

Diavolo : I....I can't tell if I'm traumatized or want to kill him...."

Barbatos :..... would you like some demonus?"

(Sorry it's short ran out of ideas)