I dont know if youll think these are dumb, but you asked so here's a few id like......You know how guys in the gym that arent your friends ask you for spots all the time while they attempt to do INSANE amounts of weights, well....
1)"No i wont spot you......so dont ask!"
2)"You know you cant do it......so just drop the weight!"
3)"Me lifting it for you doesnt count!"
4)"Just cause i can do it....doesnt mean you should try!"
Another idea is incorporating a picture of winnie the pooh somehow, and the writing saying "You Can Drink Winny?"
Another is, "I Know, I Know, If You Were Using As Much As Me, You'd Be Just As Big!"
And i dont know why, but i REALLY want a shirt that says "I LOVE COW" on it
Either way, some of the ideas ive seen are awesome, and i want some of these shirts if they are ever made! I just saw one on bodybuilding . com the other day that said "Dont talk to me, Im dieting!" I think im gonna get that one