have you cheated?

No I see no reason to do so. If you're going to be in a relationship with someone you might as well give them all your attention or just break things off.

Last time 10 ago in GTA San Andreas and never ever.
Cheating is basically for kids bcuz they're noobs from the beginning.

Never. I just fucked a lot of prostitute behind my partner back

I cheated on video games, does that count?

No, and I never will. It's a horrible thing to do and to put someone through.

Well, I've never been cheated on, but I have hooked up with a couple girls who were cheating. So, I was an accessory to it, I suppose. I was well aware. So, I'm still kinda guilty of being involved in a cheating scenario.

edit: if this is about video games, yes all the time in single player games. Never once in multiplayer.

no never,
i do not think it is worth it

no because i havent had a relationship once also ;(

I did long time ago and it was not worth it. never again

honestly if you cheat you either have personality problems, bad compatibility with your partner or mental issues, not worth it if you're committed even a little bit (which some people aren't, specially in latest generations).