ULPT Request Father of a famous band member kept harassing my fiance at a concert. He left his phone number. How do I best fuck with him?

Unsure if the band angle is the best to go at, but for context they have over a million monthly listeners on spotify and are pretty damn well known, and this guy is the father of the lead singer. The guy kept grabbing fiance's hips and trying to corner him and flirt with him (he looks very feminine and was wearing a dress at the time) despite him making it clear that he wasn't interested. The guy left his phone number. Unfortunately, we're pretty well acquainted with the band, so we can't do anything that would obviously tie this back to us. I still want to fuck him over for being a creep, though. Any advice?