issues solved 
Re: Relationship with siblings after marriage
i think you are taking this out on his gf for no reason.absolutely wrong.
Re: Relationship with siblings after marriage
I agree with Croquet, to cut her off of your friend's list on everything is a total overreaction. And what's the big deal if he told the girl the sex of the baby? Maybe he is a HAPPY mamu and wants to share the news. I think you are getting insecure that your bro is giving attention to her, and you think a portion of that attention belongs to you and your sister. Maybe things were changing, but you are definitely accelerating any negative changes by being so overdramatic. She hasn't taken over his life, but maybe he will want her to, after the females around him act so immature. I think you should add the girl back as a gesture of goodwill and apologize to your brother and the girl.
Re: Relationship with siblings after marriage
Hmm, thanks for your advice, Croquet and Jalebi121. I guess I am totally over reacting. Possibly the hormones are takin over :). And don't take me so wrong, I did it only this one time having being in contact with her for such a long time, not to mention the gazillion times that Ive spoken up for them in front of my parents.. sigh
Mods, you can close this thread. I feel all mature n grown up all of a sudden :D Thanks guys!!