It's a joke. He finds your image to be shocking, and he can't un see it, he must therefore wash his eyes. Not literally, that would hurt, but figuratively.
One of the ways our culture differs. You wear speedos, they are mobile, look comfortable, and allow you to be next to nude in public. We wear oppressive shorts, essentially swimming pants (men only), to hide our shame. Dang our Puritan heritage.
Ladies on the other hand can wear whatever (Double standard, but we seem to enjoy it).
Havasu, need some eye bleach?