When you comment on someone's post and they like your comment to end a possible awkward situation.
Ex. of The Like Slap:
Julian: *types status update* Had a good time tonight!
Maria: *types comment* I know man, especially when you made out with my sister! LOL
Julian: *Like Slaps*
When you have a long face that looks pretty pissed off.
Wow you have a face like a slapped horse