(You're playing as Remus Lupin. REMUS IS TOP AND SIRIUS IS BOTTOM.)

Remus and sirius would be best friends, yet not lovers but definitely liking eachother. Until the one day Sirius saw Remus talking to Barty Crouch Jr and got extremely jealous. He couldn't just let HIS BOY talk with Barty?! Remus was his after all and Sirius was very possessive.