42 year old married man with 2 kids+ cheating for a 22 year old girl?

Your friend isn't the first and she won't be the last for this guy. My guess is he won't meet up with her. He's having fun with emotional relationships on the internet but isn't into a physical one. Just stay out of it. Your friend will only think you are jealous.....and she will tell him. Then they will both be mad at you. Just be quiet because you can't change her mind anyway.