If you really want to mess w/ them, bring up Madjester's point. Ask them questions, instead of declining. Ask them his question, actually. See what they say. Might be fun get'em messaging back and forth with ridiculous answers.
Casual and Competitive. Hmm I think they like to mess around in custom games and be the best when serious. I would like to join, but I'm in a 2 men lone wolves team. I've always had a lone wolf attitude since Metroid Hunters.
Water-It's good for you!-- Hard games are fun... Yes, you, Dark Souls.