[peterwwillis]

Using skin grafts and prosthetics they can already create the structures they want, so this would merely make a slightly more realistic looking structure, but probably not make it 'functional'. There's a number of active processes that would have to be reproduced, and I doubt there's sufficient existing wiring/processes in place to create the same effects. If you just don't have the wiring, it's difficult to make it work organically. But I can completely believe it will be possible in the future to create synthetic pumps to induce erection, and redirecting female ejaculation through the phallus should be simple enough.