A form of smack-talk. Apply's in any means of competition whether it be video games, sports, etc. To "see someone for dessert" means that one person has already beaten his/her opponent or "eaten the main course", but the loser can have the satisfactory/consolation of a rematch or "See them for dessert", but any victory after the fact isn't as sweet.
Rob: I just beat you 4-0 in FIFA! See me for dessert