yes, it is wrong to make your bf/gf chose something like that.
if you have a problem with their friend i would say that you should tell your bf/gf but don't make them chose, i'm not sure what your problem is but i had a problem with one of my ex boyfriends friends (i HATED the girl with a passion) and he wound up dumping me for her. i told him i before i didn't really like her but i wasn't going to make him chose, i just asked him to ask her to stop throwing herself at him but my ex doesn't stand up for me or himself so he didn't and she kept throwing herself at him and then he finally decided he liked her, not sure why because she's a horrible person IMO and in many others as well, but he did.
sorry if i just vented about it i'm still really mad about it all and i know i never post on here even though i'm on everyday