Here’s my request : ) So it’s kinda long, and if you feel weird you Ofc don’t have to write it!! So y/n is marks younger sister, Ethan’s best friend, and Tylers girlfriend. It can start with like a lil smut scene and Tyler leaves hickeys on her neck and thighs. She warns him not to since they’re filming with mark later, but he doesn’t care (it’s not like gross or invading, she lets him of course but he doesn’t really care what mark thinks). They go to marks and they do like a “who knows my sister better” video between mark, ethan, and Tyler. They use an online test and mark gets increasingly annoyed with Tyler and a “favorite sex position” question comes up. Mark tries to hold back and Tyler makes a joke just like “not for you to know, but I should get the point for that question” or something, and Ethan’s like “I probably know too” you know joking and mark loses his cool and brings Tyler outside. They argue because y/n is way (not too much) younger and she’s marks sister and mark is angry and tries to hit tyler. Tyler holds him back against the wall and mark realizes what he just did and he just goes up to his room. Amy calms him down and later they all talk and apologize and it’s better and they decide not to do that video