Mom has a Thorough Investment in this Family Lineage

(Somehow my mom and I ended up talking about penises, I was trying to change subject.) Me: Anyways how was- Mom: Just so you know you're not allowed to marry a man with a small penis. Me: ...what? Mom: Yeah. I don't want any small penises messing up our family genes. Me: What?! Mom: What? Do you really want me to tell you about your father's? Me: No! No, No. No. Mom: Cause he was huuuuge! Me: Oh my God, mom!