This is a German joke, but I think I found a way to translate it:
A girl wants to introduce her new boyfriend to her parents. He knocks on the door and the parents together open the door and introduce themselves: “Hi, my name is Sarah and this is my husband Michael, nice to meet you!”. The girls boyfriend shakes their hands and says: “Nice to meet you too. My name is Tobias and I am here to fu*k your daughter.”. The father stares at him shocked and says angrily: “Excuse me?? To what?!” “It’s Tobias, but you can call me Tobi if you like”, he responds and walks in.
