But the student of human nature in me says that, when your sister gets kissed and you don't, it's quite possible that the unhappy hormones end up standing at the gate.
From my studies, I would postulate that conjoined twins probably end up having less sex than average people, and that is not only because sex partners are harder to find when you're conjoined.
Bethanye Blount came into work early to interview a job applicant.
A veteran software engineer then in her 30s, Blount held a senior position at the company that runs Second Life, the online virtual world.
If one has an orgasm, does the other enjoy the same, however unwittingly? Conjoined twins, like the rest of us, tend not to talk in great depth publicly about their most intimate moments.
If twins share one set of genitals, they're both going to feel any touching down there.
So, I suppose I should get to what the people really want to know: what do conjoined twins feel when they have sex?
If one is sexually stimulated, does the other feel it?
They may just not desperately need a third, just as most of us with a second to whom we are very attached don't need a third -- even when the sex gets old.
But when a conjoined twin has sex with a third person, is the sex -- by virtue of the conjoinment -- incestuous?