Go head and try it for free.
There are multiple people coding big cocks, pierced cocks, horse cocks &c.
There is even an API so you can run programs that male and female parts can interact with each other. I know one guy that is working on this API to interface to objects in real life that are hooked up to your computer.
In the end you can have sex with a partner through the second life interface playing with something other than a keyboard, mouse, microphone or speakers.