As long as no laws are being broken then I don't think it's a issue.
I've seen documentaries on tv of 70year olds with 30 year olds, but the main thing is they're happy. who are we to judge?
Some see it as wrong 2 people being in love, yet its perfectly fine to cheat and have every tom,dick and harry inside you.
People are just messed up in the head, nothing better to do than make their life seem so perfect and mess with someone elses.