I wouldn't mind if my boyfriend had pictures of a celebrity that was posed respectfully or if it was promoting some movie/show he was into, but there's definitely a line there that could get crossed. Don't get me wrong, I'm not naive enough to think that just because a guy is in a relationship and totally committed/faithful he's not going to look at any girl but me, but I'd take issue if he was flaunting the fact as his wallpaper. It's the same as a guy blatantly oggling other girls while I'm standing right next to him. IMO, that's something to do around your buddies and away from me - and doing otherwise shows disrespect (not to mention maturity implications). Ultimately it boils down to the fact that I know I'm not the only girl in this world, but around him, I kinda want to feel like I am.