Dad: What did your older brother say before he lost his virginity?
Son: Dad, please don't.
Dad: Exactly.
Dad: What did your older brother say before he lost his virginity?
Son: Dad, please don't.
Dad: Exactly.
Listen up, buttercup. The punchline is that the older brother probably said, "Dad, please don't" before losing his v-card. Your dad is a boomer and thinks this is funny. I bet you have a participation trophy.