Brendan Behan, according to his biographer Michael O'Sullivan, was bisexual. He seems to first have had honosexual relations during his borstal years. Outwith borstal and prison, the only verifiable homosexual relationship was with a man called Peter Arthurs, whose frank account O'Sullivan quotes. Behan was also married, of course, to a woman.                                                      

Read BB's "Confessions of an Irish Rebel", nothing about homosexuality in it, or much to do with reality, but it's very funny.