I noticed the level of possibly-necessity-induced-heterosexism in the counsellor's speech ("Our husbands and wives..."), but even in overtly hetero arenas, people bump into those they don't necessarily want to have sex with, regardless of plumbing. It made the whole thing decidedly unnatural to me, and thus I assume it was a specific editing decision based not so much on diegetic logic as contemporary attitude (can't even potentially alienate the majority fan base (which is also why I assume the philosophy was so dumbed down. If only the Wachowskis were French; then you'd have kick ass action and really dense philosophy. The kids would have to see it again and again to try and "get" it all. Hey, maybe I should do marketing or something...)).