I have a friend who said she was with this guys the other night and he totally had no clue what he was doing. She said she thinks he thought he was rubbing her clit but it felt like he was digging for something. Anyway I guess by the time he was ready to "slide" in she was dry and said it was horribly uncomfortable. So I say keep it just incase you run up on some dumbass like that.
Ahh, better yet just do what I told her she should have done and just politely get up and leave.