M0T said:I can't see why he would do it.
He does know what she is like, and he knows that in the past she has told him total lies when he asked her why she did some of the things she did, so I can't believe he would fall for it.
I would suggest expaining to your friend that it is none of his sodding buisness, if he is your friend he will back of, if he likes your sister more for some strange reason then tell him polietly to **** off as he seems willing to fight to stay around your sister.
KaHn