NTA, although I think your wife might have some doubt about your sexuality, probably from listening to whoever she hangs out with, telling her that you might be gay or bi.

I might be projecting here, but i was in a relationship with a gay guy for 8 years, and i had a couple of friends that have been telling me that he might be gay but i had always ignored it or get really offended when they said that. I did exactly what your wife did to you to my then ex boyfriend, asking him if he wants to sleep with who and who and how I think it would be really hot.

I am not saying that you are gay, but his response was very much like yours. So, by you getting very defensive at her, might make her feel more insecure. What i think you should do is assure her that you love her and there is no way in hell that you will ever leave her for a man.