Just throwing this note out here, because sometimes people don't understand the distinction between sexual attraction and romantic attraction. The two are not actually one and the same, something that can be seen quite clearly amongst asexuals who still feel romantic attraction and aromantics who feel sexual attraction. Considering those are possible, it's entirely possible for a person to be sexually attracted to men, but romantically attracted to women. If you've ever heard of a bisexual person who only ever has long lasting relationships with one gender, it doesn't mean they aren't actually bisexual, it could simply mean that they are simply not biromantic as well. The two do not, and probably don't more often than we are aware, have to match up. Romantic love doesn't require sexual attraction, and sexual attraction certainly doesn't have to have romantic attraction, the two often go hand in hand, so it's hard to separate them (especially romantic attraction without sexual attraction), but they are actually distinct things.
I'm not saying that that is necessarily what's happening here, but recall how Mr. Fahrenheit said there are two kinds of love. The kind you get hard for and the kind you don't. To me, that sound like a pretty good description of sexual vs romantic attraction. It's entirely possible Andou is homosexual but biromantic, meaning although he only has "hard" (sexual) love for men, he could have "soft" (romantic) love for either/any gender. Does that make him "less" homosexual? Not at all.
In this particular context Sexual attraction is defined as physical attraction to or desire to have sex with a particular person/gender.
Romantic attraction is the desire to have romantic relations with someone (living together, spending time together, pretty much any thing outside of sexual contact. Cuddling and kissing of a non-sexual nature can fit under romantic attraction.)