First: Let's think about lesbian porn. Notice how the lesbian sexuality has become fetishized in our society. It is not an independent sexuality for women, rather, it is a sexuality presented in a way that is meant to please men. It is crafted in a way that's not intended for women viewers, but male viewers. Why? Because at the end of the day, the societal construct dictates that females are considered to exist for the pleasure of men.
Second: Let's look at gay men. When arguments arise against homosexuality, condemnation of gay males usually comes before condemnation of gay women. In contrast to the fetishism of lesbian porn intended for men, gay relations are criticized because they apparently "feminize" the male figure. It is socially assumed that one or both males in a homosexual relationship must be "the woman". And since we live in a society in which masculinity is preferred over femininity, this becomes construed as a problem.
Essentially, the treatment, presentation, and revulsion towards homosexuals stem from social concern regarding the state of masculinity. This insecurity is ultimately perpetuated by our patriarchal society.
I'll give it a shot. I didn't have an answer at first, but now I think I'm starting to see the relationship between the two. 2sense had a better explanation than I, so instead of repeating it poorly I will try to simply add to their argument. The belief that human relationships should consist of consist of at least a male/female pair rests on the notion that people fall into one if these two binary options. It does not reflect the fact that peoples' measure of sex and conception of gender are social-linguistic structures. Humans cannot be so easily reduced to "male" or "female." These words reflect categories, but people, all people, have unique gender/sexual expression that as a whole transcend these boundaries. Even people who are entrenched in gender binary culture exhibit behavior and traits that freely extend across the artificial divide. Thus, heteronormativity and homophobia are predicated on the notion of clear distinctions between the sexes/genders and stereotypical adherence to the same in all parties.
Now saying it correlates with sexism? Let's be frank here, you homosexuals are going completely out of your minds. Sex is a biological born trait, homosexuality is an emotionally developed state related to sexual preferences. A woman cannot disguise as a man and go to the urinal and piss into it and pass off as a man. You cannot have a man dress up as a woman and have sex with a man and produce a child because of their sex.
You cannot fool nature.
Homophobia is prejudice against people who are attracted to the same sex.
Sexism is prejudice against people of the opposite sex.
Homophobia is when someone thinks it's "unnatural" "sinful" or "just plain old bad" for people of the same sex to have relations. It's also staying away from homosexual people, stereotyping them, and assuming all gay people will try to hit on you.
Sexism is the idealism that people of the opposite sex are lower than you. In pretty much all cases of sexism, it's men being sexist to women. So sexism is when a man assumes he's better than a woman, due only to the gender separation.
Also, no, men aren't biologically stronger than women. Yes, women have evolved to carry children, but if a woman does strength workouts just as much as a bodybuilder, than I guarantee she would be equal to him. Also, men aren't automatically stronger than women. If a man does very little to improve his physical strength, he won't be strong. As a guy who rarely works out, I can say with complete honesty that I'm sure every woman I've come across could beat me to the ground, workout or not.
I'm getting off topic. The point is, sexism and homophobia are very different things. Very very different.
When it has nothing to do with the opposite sex, and everything to do with the fact that the PHYSICAL SEX they have is with men like THEM. That potentially to someone with a traumatic past experience, old school values could make them uncomfortable. It's the right.
I actually have gay friends but I admit I don't like the presence of overly FEMININE gay males that don't look like females. If they play the whole role that is a different story. But SUPER Feminine acting/speaking gay guys are simply annoying to me. Does that make me homophobic? How if I have gay friends?