Anal play has nothing to do with being homosexual or bicurious. There are non-straight men who don't like anal play just as there are straight men who don't.
The only thing that would make a man's sexual orientation bicurious or bisexual is if they are interested in having sex with both men and women.
The only thing that would make a man's sexual orientation bicurious or bisexual is if they are interested in having sex with both men and women.