Aw hell no. We used to share, but me and my sis kinda hate each other now. And I will never forgive her, for two things;
I lent her my copy of FF7, without having finished it myself (not even finished disc1). I get it back quickly, and decide to play, only to find disc 1 missing. That was... 4 years ago. Thanks to her, I have a very expensive, but completely useless game, that I will never be able to play again.
My mum guilted me into looking past that, and then lent her my Kingdom Hearts. When that game disappeared, and she denied ever borrowing it, I went to her room, found the cover on her filthy, messy floor, and the disc, silver-side up on her bed-stand underneath garbage and a week-old plate. Thanks!
Thankfully she doesn't have a 360, and I've hidden my playstation games, so that shouldn't happen again. She has a ugly habit with just grabbing things from my room, just had to be done. >_<