Your best friend can be a couple with your EXGirlFriend?????

Well that depends on why she is my Ex. If she was unhappy with me and chose my best friend then i have nothing to do with them. If i was not happy with her and left her for some reason then i guess i care a damn about who she hangs out with. Well if she was with me and trying to build a realtionship with my friend then i will be a bit concerned and will see to do what best i can to retain her back. Relationship once lost is always difficult to get back, so there is nothing we can do when she is an EX to me.