Don't think Mel Brooks.
Think Bob Newhart. Play the straight man. If they want to play it like 'The Mummy' or some other wise cracking low brow adventure, that's there decision. Keep a straight face. So straight that its funny, or at least a good surface to bounce jokes off of.
It doesn't sound like you are going to change the players at this point, but if it was me it wouldn't be the comedy that would bother me. Actually playing your character for laughs is extremely entertaining for me as a DM, especially if you are actually funny. What would bother me is if they couldn't stay in character. A funny in character quip is one thing, but continual out of character banter suggests either immaturity or boredom or both. I don't DM just to hear myself talk. If I'm not entertaining you, why should I waste my time? If you don't entertain me, I'm not going to stay interested in doing the work to produce fun sessions for you. Let's play something everyone can keep thier minds on, or watch a movie or something.