A young man (boy really) comes home from school and tells his dad that he is no longer a virgin. He had his first sex today, with one of his teachers, no less.
Dad's eyes light up. "Son, I'm proud of you", he says, "why, I was 16 before I had my first sex". Anyway son, you're a man now, so I think it is will be OK for you to have a beer with me"
Dad opens two beers, gives one to son and takes the other for himself. "OK son sit down and tell me all about it" He says.
"Sure dad", says son," but if you don't mind I'll stand up for a bit, my bum is still a bit sore from all that sex"