"There's something I need to tell you first. When you were caught in that explosion, you were contanimated with mutant DNA. It repaired your body, but also had other effects on you. We're going to slowly turn the lights on. There's a mirror next to your bed so you can see more clearly. Prepare yourself and don't be too shocked."
The lights came on and Rick saw his body - and nearly passed out again.
He was a girl. An honest to God Female. He had The biggest boobs he had ever seen. Even this thought aroused the male part of his brain. He suddenly felt liquid flowing out of what he assumed to be his Vagina.
"Good, You're already wet." Said the doctor. Rick thought of what this meant for girls. When the Doctor puled down his pants, showing a erection beyond that rick had ever had, rick knew what would happen.
The doctor Pulled Rick's clothes off, locked the room door and jumped on rick's bed. He stuck his massive cock into Rick's feminine hole. Rick and the doctor than engaged in the best sex he had ever had.