Why do I feel bad..

K
I was talking to a guy off of a dating app for a couple of weeks and snapchatting him when I thought to look him up on Facebook and found out he has a wife.. A pregnant wife. I immediately contacted her and explained the situation and she just responded to me tonight telling me thank you for telling her. But why do I feel bad for the cheating husband? I know it was the right thing to do, but I feel bad that I put him in that spot.