Theirs(MarkxreaderxDerek)

What if when Mark and Derek where early adults They had a threesome with a girl they where both obsessed with. But when she moved away they tried to move on. Derek met Addison and used her to get over 'their girl', while Mark became a man whore. Derek married Addison a year after meeting. Two years later mark slept with Addison and Derek found out. She thought he was mad at her because he kicked her oUt. The whole thing was staged she Derek could get away from her because she was extremely jealous and just over all a bitch. He pretended To be mad and moved to Seattle Because he got a better job there and didn't Want her anymore. He ended up having A one night stand with Meredith and she became addicted to him trying to find him. What happens when the interns come and the girl he and mark have always been obsessed with is one?

(I know this probably doesn't make sense but just roll with it)

Mark Sloan x reader x Derek Shepherd

I do not own greys anatomy or any pictures but I do own Thalia and her backstory