https://en.wikipedia.org/wiki/Latent_homosexuality
This explains a lot about why the mere idea of men wearing women's sexy underthings might evoke all of this imagery about butt play. Shows that 80% of guys with homophobia are aroused by homoerotica, compared to 24% in non-homophobic men.
Not saying that you're one of the 80%, you might be in the 20% group. But it shows there is a link between homophobia and latent homosexuality, and this is the most likely scenario.
Denial, not just a river in Egypt, indeed.
https://en.wikipedia.org/wiki/Homophobia
"Homophobia encompasses a range of negative attitudes and feelings toward homosexuality or people who are identified or perceived as being lesbian, gay, bisexual or transgender (LGBT). It has been defined as contempt, prejudice, aversion, hatred or antipathy, may be based on irrational fear, and is often related to religious beliefs."