My parents have never really said anything embarrassing about sex in front of me. However, I recall many times trying to watch TV while they were in their room alone. I'd hear this SMACK SMACK SMACK. For years I've told myself it was just dad slapping his knee because of a funny joke. FarmerHedgehog is a sick and twisted woman and tells me dad is slapping something besides his own knee. Maybe he's smacking his thigh?
On another note, mom used to read my mail even when I moved into my own apartment. One time my parents were coming over, I stuck a used condom in the middle of a card I'd gotten to break the habit. Mom got this horrid look on her face when she found it, but dad just gave me a GOOD JOB look.
At a family reunion, my aunt was asking everyone if they knew what the word fellatio meant since she'd heard it on tv.
At the dinner after Grandma's funeral, the fair included hotlinks. Her nephew, a pastor, forked one and said, "In Kentucky we call this a Tube steak". Unable to keep my mouth shut, I replied "We call something else a Tube-steak in Oklahoma." Then I turned to the wife and offered to feed her one that night. Half the family was offended, the other half was trying not to choke while laughing.