A gay man agreed that he had sex with many straight men and the appeal of gay sex to straight men is evident. Doesn't this prove anything?
The number of supposedly straight men who get engaged in gay sex is enormous. I think what is known is only the tip of the iceberg, and many straight men have sex with guys. Some of them still act as the active partner and have their cocks sucked, then penetrate the passive guy. Some go both ways... But, I think the appeal of gay sex to straight guys is quite evident and the anonymity of sex as well as the illusion of keeping the straightness also helps.