My Girl friend

I had a friend. A girl that I use to share room with years ago. So recently she met a guy. Lets call him Z.   Z is a little unknown celebrity. Very fast they became "One night stand" buddies. Few days ago  Z's brother texted my friend through FB. Asking her out for a drink. My friend thought it was sweet but its also weird at the same time. My friend told me about it and I thought it was cute but I think its best she inform Z. Just a little FYI. He has no right to stop her if she wants to go out with him anyway.  She then informed Z about it and Z was okay with it. In fact he laughed about it.
Yesterday my friend got a call from Z. Asking her out for a drink with his brother. So my friend agreed and thought it was a nice gesture of Z and kinda sweet.  My friend still feels weird though, of the brother situation thingy. Anyway she reached the place and they had drinks and they were laughing about it. So at the mids of it... Z's brother went to the loo. Z then holds my friend's hand and start whispering to her. Z actually ask if my friend would have sex together with his brother.
hUH??? I know both of them are damm sexy but I really don't think that is possible and really? Really a guy would really do that? Fuck the same girl with his brother at the same time???  If I am my friend? I'll just walk away or go home, but my friend did manage to stay and decline and have a good time. According to her.... She doesn't want to loose a good fuck!!! Hahahhaahah..... Ah well, as long as she knows how to guard her flower then I am okay with it.