Son-in-law.

Dad catches his daughter in her room with a vibrator! He asks: ”WTF is going on here?" Daughter: "Dad, I’m not going to get married so it’s not that bad!" One Saturday she comes home to find her father in front of the TV, watching rugby with a beer and a vibrator in his hand. Daughter: "WTF is this?” Dad:" I’m just watching some sport with my son-in-law.”