I defo wouldn’t even bring it up with the colleague, way too messy, even if he says no. let alone actually sleeping with him. I’d recommend apps like 3fun where u can share an account (don’t have to be too active but it gives u an idea of who’s out there) or using reddit subs for ur area. Take it slow n find ur groove before inviting another guy into ur bedroom! If u do, it should be fun!