Inland, you could try this:" I am a cougar- i have my pick of a gaggle of testosterone -filled single 20-something boys, and you think that you, a married guy with a viagra prescription, are even in the running? You're embarassing both of us."
Or: "Dude I look like crap, I'm crabby and you're my married crew who just blew three tacks in a row- either you think my self-esteem sucks so bad that i think you are a catch, or your self esteem is so crappy that i am all you can get. either way you just insulted me."
or there is always the simple " get the f**k away before i talk to your wife."
Or you could simply take it as the compliment that it is, and blow it off.