Let's talk about something else for a moment.

Hedgewars is a great game, being (IMO) the true sequel to Worms Armageddon...and yet one JessMaestro, who likes talking about poop (at one point having a whole team themed on "The Brown Stuff") and making me look like a fool because I complain about him, tries to ruin the fun. Today I ended up in a match with him, and his team didn't have any references to excrement. He then said "Poopsie". I say something to the effect that I thought he was coming close to being mature. Then he and another player gang up on me and mock me, talking about "how you can't be immature with a game about war" and that I "should stop killing other hogs", etc. I then ragequitted. Hedgewars, like its inspiration, is a rather silly game. By maturity I meant "not using toilet humor", but I didn't say that.

I try to avoid servers where he is a player, but that isn't always possible.

What should I do the next time I'm faced in that situation? What should I say?