Is it normal that i like thinking nasty things about my grandpa?

Is it normal that when i think of my grandpa sucking on a live tuna and hitting midgets with mexican corn while they pull out his pubic hair 1 by 1 turns me on. Sometimes i like to set up my stuffed animals and pretend that they are the midgets and i am my grandpa, then i take tweezers and pull out some pubs. But mostly i like to tell my grandpa about it cuz it turns me on to know he thinks about it too. is this normal???