Not a joke per se', but I stumbled across this dude's youtube channel while I was supposed to be working and haven't stopped laughing since. My boss is going to love my internet report when he gets it.
I admit, I do have an immature sense of humor, but you're the creepy one if you're thinking about him masturbating.
I used to work with this guy. Kind of offbeat but I didn't know how weird he was until a woman told me he was the shoe man. The guy had come in a bar I was in and was sitting next to me. When he got up to go to the bathroom she asked me what I was doing hanging around with him. She was a regular in the bar. She would come in after her shift at a strip club. She said he would come into the club and offer the strippers money if they would watch him beat off while he looked at their shoes. He was later arrested for breaking into women's homes and masturbating while playing with their shoes.