Lol no. None of the members are (at least.. they haven't come out).
He does like to kiss the members sometimes, but most of the time it's just for fanservice. Sometimes the other members kiss each other as well.
If you are talking about T.O.P. from Big Bang then NO he isn't gay.Unless you are talking about another Choi Seunghyun then I am not sure because there might be hundreds of boys named "Seunghyun"
He is straight. He was just acting as a gay guy in the drama Personal Taste.
The character of Flapjack is not written with sexual orientation
Nothing is known of her sexual orientation.
The Joker's sexual orientation is not written into his character.
Soko's sexual orientation is heterosexual/straight.
The fictional character of Yoshi is not depicted with sexual orientation.
The sexual orientation of David Rodriguez is unknown.
Matt Evers' sexual orientation is not known.
The SNL character "Gilly" was not written with sexual orientation.
Frankie Muniz has not stated his sexual orientation.
I think you mistake "sexual orientation" with specific types of orientation. Sexual orientation is a part of every humans make up. A person can not have a sexual orientation. Your sexual orientation is what makes you gay, straight or bisexual. Homosexuality IS illegal in some countries. You can outlaw a behavior but you can't outlaw an urge or feeling.