The girl probably just wants power, power over both of you. Why fooling around with your friend only when she can have both of you.
Try to imagine the situation for yourself (the other way round):
You have two girls who are best friends.
Both of them like you very much to the point that kissing and going out and stuff is involved.
One is shy, the other isn't.
Why should you ever chose one as long as you can have both?
This "threesome" is spicing things up, making the whole kissing behind each others backs and things more interesting.
You really want my fully fledged mysantropic opinion on this:
Dump the girl,
explain the situation to your friend and if he doesn't dump the girl too, dump him instead...
Start going to look for the nice girls around, you know, those who have like a working moral system and family values and stuff. Difficult to find but well worth the price ähh sorry prize...
Try to imagine the situation for yourself (the other way round):
You have two girls who are best friends.
Both of them like you very much to the point that kissing and going out and stuff is involved.
One is shy, the other isn't.
Why should you ever chose one as long as you can have both?
This "threesome" is spicing things up, making the whole kissing behind each others backs and things more interesting.
You really want my fully fledged mysantropic opinion on this:
Dump the girl,
explain the situation to your friend and if he doesn't dump the girl too, dump him instead...
Start going to look for the nice girls around, you know, those who have like a working moral system and family values and stuff. Difficult to find but well worth the price ähh sorry prize...