Is a straight guy considered gay if a girl tricks him into a gay cock sucking by blindfolding him?

My girlfriend of 4 years loves watching guys have gay oral sex. One time it was only me and her in the bedroom, and she blindfolded me and said she was going to give me a *******. So i said ok. She said she was leaving the bedroom to go to the washroom and she said will be right back. When she got back i could feel her lips sucking on my penis. I was so happy when i felt her giving me a handjob and a *******, that the next thing i do is take off the blindfold and remember seeing her OLD BOYFRIEND sucking my manhood and giving me a handjob. All along i though it was HER not HIM. i said HEY what the heck? She started giggling and laughing and thought it was really funny. In fact they were both laughing. I told her to stop this and still to this day she keeps doing it and laughing at me. Her old boyfriend is gay and loves giving gay oral sex to other guys. She is still also trying to get me to have gay sex with her old boyfriend. I keep telling her no. She keeps telling me how much it would turn her on alot. Should i leave the relationship and move on or stay and play around with her crazy tactics?