Kiss the Girls

Every song in this film serves a purpose and adds to the story. However, I can't figure out what the point of the song "Kiss the Girls" is. I would understand it if John had committed adultery or was a rapist or a pedophile, but he was a grief stricken father who decided to off himself. Granted, it goes along with the kissing booth where the Painted Doll is working, but even that didn't make much sense to me. It all just feels so out of place. The only thing I can come up with is that perhaps it went along with his dead son he was looking for (like kissing girls on the play ground) but that still seems like a pretty weak explanation. Any ideas?