Ok, so this one will be a lemon chapter!

1. Make up your own!

2. Sans had been captive to fell and edge for a long time as there servant. As in, helping them with their heats (as to why he had a box of 'toys' next to his bed), doing chores, comforting them from time to time. It was an ok job. He was currently in the basement, his heat hitting him hard. He vowed to fuck this first person that walked into the basement. As soon as he vowed this, Fell had walked downstairs, sans' food in his hands. Sans grinned and knocked Fell out, tieing him to a chair and waited for him to wake up, ready to get rid of his heat. 

3. Fell and classic had been friends for a long time and Sans wanted to make them a thing, having had feelings for fell for a long time. Whilst fell was making food for the two, sans groped fell's breasts as he had his female for on.  Fell moaned, still trying to cook as Sans groping him and, in the end, fucking him.

4. Fell and sans had been dating for a long time. Whilst sans was outside, he saw Fell talking to another monster... Sans' yandere instincts kicked in and he fired a bone, stabbing the monster in the soul and dusting them instantly.  Fell looked at Sans in fear before running. Sans teleported in front of his senpai, pinning him to a tree.  An angry argument happened between the two,  ending with sans fucking Fell.