You Signed Up For This

Regulus’ best friend Dorcas convinces him to go on a summer trip with her. She dubs it ‘operation make Reg smile again'. It's his chance to break from the cycle of toxic mistakes he keeps repeating in London.
James wouldn’t know casual if she walked up to him and introduced herself. That’s why he’s got a rule to protect himself from heartbreak: only hook up with tourists on their last night in town.
When James learns the gorgeous tourist he’s just met is around for six weeks, he gets spooked.
Six weeks is a long time, but also no time at all. As the Black brothers unexpectedly reunite after ten years apart, James and Regulus are forced to spend time together and James starts to think that maybe rules are meant to be broken.
Getting involved with Regulus is going to hurt, but James believes it'll be worth it. Either way, James knows what he signed up for. Or does he?

OR

James and Regulus have a summer fling that they promised their friends they wouldn’t have. Remus and Sirius discover their mutual hatred is just pent-up sexual tension. Dorcas and Marlene are always winning, even when they’re not.
It’s a cruel summer for all.
I love you (ain’t that the worst thing you ever heard?)