How is that funny?
Earth to Marc...
Often comedy plays off irony.
Usually a when someone breaks bad news to a parent about his/her sexuality it's to tell them they are Gay.
So when you reverse the situation and the bad news is that she is longer a lesbian, it's funny that the parents take the news hard because they are so liberal and will be embarrassed in front of their friends..
See ?..Comedy..Irony and reversering what is normal is usually funny.
Maybe I can post the clip and you and Norm can find someone to walk you through it.