I wonder what the reaction would be if anyone made jokes about Clinton doing Chelsea. Bill, not Hillary.;)
In no way do I mean to defend SNL's poor taste, but I do remember a skit in which Slick Willie and family (including a singularly unattractive "Chelsea") are watching a performance by (SNL guest) Madonna. Bill is obviously leering at Madonna, but Madonna singles out Chelsea as the object of her lewd intentions.