I'm so sorry, dump his ass if you haven't already, act all sweet like "oh no it's ok I forgive you blah blah blah" then just go "oh and I almost forgot! you suck, we're done" you can do WAY better than that jerk
*sigh* Just to explain it to the basics downvoting : If she surprises him, it probably is something he really enjoys. And if she knows that he really likes it, yet she has to surprise him with it, they have some talking to do. I probably should have frased my first comment a little better. What I meant was that if she has to surprise her boyfriend with sex, sooner or later they're gonna either break up or he is gonna cheat.
With a knife.
2)stitch small patches of sandpaper into them
3)Act natural
4)Let the rest take its course.
Another idea would be wrapping his crotch region in ductape, so he has to peel it off.