Nadz, this is not unheard of, we have friends who have been married for over 2 years yet BIL is still so close to her, her hubby doesnt seem to mind?!
Me and hubby thought it bizaar how they would share a plate (heellllooo), and even walk hand in hand (!!!) all in front of hubby.
Now that she is pregnant, BIL seems to be taking more care of her than her hubby, but like i said they all seem to be more than happy with each other (all from Pak BTW)
We still think its weird