Perhapse humans just generally enjoy pleasure, and these concepts of "strait/bisexual/lesbian/gay" are just labels conditioned on us by society. after all, if people can be raised in a fanatically religious environment and eventually believe they're actually talking to god, could we not be raised in an environment to make us strait, when in reality we'd be fucking whoever? maybe gays/lesbians/bisexuals are really just people who aren't easily conditioned in regards to their sexuality.