Sci-fi au from the outside a new crew member joins the ship, and not long into the trip the whole thing starts shaking. They panic because that can’t be normal, and starts running for the escape pods. Only they realize no one else has moved? All of them are just going about their jobs, while the giant metal tube they’re in shakes around them.
One of the veteran crew members having to take the newbie aside and explain that the odd cyborg that they saw in orientation and the ship are a thing, and this is their sex, and oh look work to do no need to think to hard on this.