Well the big thing is can you trust her not to talk. Also does your wife know about this fetish you have? If she does and is okay with you doing this it is not cheating. It would be a bit of swinging. Now if your wife is not supporting your fetish it would be cheating. In that case you need to evaluate if the woman is trustworthy. If you feel she is or your wife is okay with this. I say go forth and have fun. Just make sure you do not do anything stupid.
The best thing in life is a willing submissive with a red ass.
