The problem with tit fucking is that it tries to mimic thrusting into the lower half while being so incredibly close to oral that it makes you wonder why she isn't just throating your cock. Boobs are best when sucked or grabbed, and while rubbing your dick against them can be fun, it quickly turns silly once that's made the focus.
Most IRL women think it's fucking dumb too, and will mock their boyfriends for enjoying it