he wants to try and beat you so he doesn't look bad
Things some chess players say when they blunder
There was an older gentleman at a club I used to play in, and when he made a losing move he'd double over and shout 'ow!ow!ow!' He appeared to be in genuine, physical pain, poor fellow.

Wow, how can he hurt himself after he makes a blunder unless he does on purpose. Kinda don't understand lol
Once, after i saced 2 bishops and a rook to mate my opponent, he instantly requests rematch, and types "YOU BETTER!"