A boat salesman shows the main characters a "nudie photo" and makes a suggestive comment you're not allowed to touch or play as a metaphor to get them interested in a boat they are thinking of buying. However no nudity is actually shown in the photo.
When Joe and Gus hear an approaching boat and wonder who it is, Joe says, "remember that movie Deliverance? It sounds like those guys." Banjo music briefly plays, Gus starts to whine and says, "Joe, I don't wanna squeal like a pig", to which Joe, also whining, says, "I don't wanna squeal like a pig either."