Oh, well now you're making him sound quite likeable! OK, so no sharp elbows. What about a little shove then, or poking your tongue out at him, or just rolling your eyes.... That ought to help.
See, I've got all wound up now & no-one to elbow-poke. Hah! Gawd help poor Mark tonight when I get home with all this pent-up strop (actually, scratch that - it sounds too much like the fat dominatrix thing_).