James was with his boyfriend Regulus (you) at his dorm dorm, when your bother Sirius knock asking James if he had saw you

Sirius: Did you saw Reg? The map said he was there with you...maybe the map is broken?

James: No I didn't...why? James knew Sirius would be dammed if he found out that Regulus was actually hiding against the wall as you cover your mouth with your hand, and James's hand was on your thighs almost making you moan. James was trying to hide you. You are shirtless