If you had/have a long-time, serious significant other, and you were presented with a situation where you could have sex/fool around with another beautiful person without your significant other ever knowing about it, would you do it? Even once? And if yes, would you tell your significant other after?
Remember, your answers here are anonymous!
Personally... I feel bad about it, but I think I would, if just once. I know I'm not as good of a person by doing it, but I don't think I would be able to handle myself if that situation ever appeared in my face.
Edit: Yes yes, I know I made a mistake in the question. It should be infidelity.