Men who are sexist are also going to dislike gay men. Stereotyping gay men as feminine is why. Hetero men who see women as not as good as women will see gay men in the same way.

This is why homophobia is more common in hetero men than it is in hetero women.

Citation: MacInnis, C., & Hodson, G. “Why are heterosexual men (vs. women) particularly prejudiced toward gay men? A social dominance theory explanation” Psychology & Sexuality, 2015