Orgasm is something that's generated entirely within the nervous system. As long as the nerves of the transplanted penis are properly hooked up to the right pat

Orgasm is something that's generated entirely within the nervous system. As long as the nerves of the transplanted penis are properly hooked up to the right pathways, you can orgasm, though it will take some healing time for the nerves to come fully online. You don't need to have an erection or be able to ejaculate semen in order to orgasm. Most men associate orgasm with both, but neither is strictly necessary. Speaking of erections (probably the only time I will ever write these words on HN), they too are not dependent on having testes. Erection is a vascular response within the penis: much of the internal structure of the penis consists of sponge-like tissue that stiffens when filled with blood. Assuming the relevant blood vessels and nerves are properly hooked up, erection should be possible. Of course, you need to take into account healing time and the surgeons doing a perfect job hooking everything up. Testosterone plays a role in signalling for an erection, but you don't need testes for that either: the adrenal glands produce a small amount of testosterone, and exogenous testosterone such as from an injection, a patch, or a gel works just as well (and I would be very much shocked if this guy wasn't on exogenous T already). And in the absence of testosterone entirely, there's always Viagra. And some people can still achieve erections in the absence of testosterone even without Viagra, but this is extremely YMMV. He might even be able to ejaculate if everything is hooked up right, but it'll be watery seminal fluid without sperm. Though that does bring up one difference between this guy and a guy with testes: he's still going to have to take exogenous testosterone for the rest of his life for the sake of his mental health, body shape, and bones. And he'll never be able to conceive, of course.