Buy a pork butt and some chicken, cook those and tell him this is what was in the package. maybe throw some frog legs on just to mess with him...
Either that or go talk with him about your concerns and see what he says. He trusts you enough to cook for the group, I would assume he would respect you enought to understand your concerns.
55gal Black UDS
85gal XL UDS
DUCAN Affinity - gasser
Mini WSM (For the 11 yr old of course)
Extreme amounts of awesome to assist
11yr old who loves to cook, and an 8 yr old who is