Alyson Krueger in NYT on virtual sex:

'Certainly partners will also have to negotiate whether virtual-reality sex constitutes cheating. It is, after all, much more lifelike than traditional pornography.

But Mr. McMullen said a lot of people accuse his sex robot of doing that, but he believes he is helping alleviate a bad situation, not causing it. “There are people who are already lonely, and people who live their lives being alone. They work all day and come home to an empty house,” he said. “This is just offering an alternative to those types of people. They don’t have anyone else.”'

Read the article here.

Is sex with a robot cheating?

Perhaps you should tell your partner: "I'd like to cheat you, do you prefer me to have a robot-lover or a human-over?"