You hear the front door open and shut. Your girlfriend is home and hopefully see can help you. She walks in to see you sitting on the bed and drops the mail and her purse with surprise.
"I think I'm turning into a frog" you say. "What should I do?"
She stares at you in disbelief.
"This is no joke" you insist.
"Did you put on some webbed gloves and swim flippers from the closet?" she asks.
"Yeah, but I was just curious and wasn't expecting this to happen."
"You should get in the shower before you dry out."
"But this seemed to start happening after I spilled some water on myself. Couldn't a shower cause the changes to spread faster?"
"Everything will be fine. Trust me."
"Okay."
You stand up and walk into the bathroom, but notice you girlfriend is watching you intently as you do so. You turn on the shower and step in. The warm water causes you to immediately start feeling better. In fact, you've never felt so amazing from a shower before. Then you look at your arms and legs. The change of your skin to green and hairless is definitely progressing faster.
"I thought you said everything would be fine if I took a shower?" you call out to your girlfriend.
The shower door opens and your girlfriend walks naked to join you. Her nipples are hard and she's visibly wet. "Everything IS fine. This is turning out just as I'd hoped."
You hold up your webbed hands. "This was your idea?"
"I didn't mean for you to find out like this. I was going to ask you to put the gloves and flippers on the next time we decided to be a little adventurous."
"But why turn me into a frog man?"
"You remember that movie we saw, The Shape Of Water? How the woman has sex with the amphibian monster?"
"Yeah."
"Ever since we saw that I keep fantasizing about you turning into an amphibian man and having sex with me. Then I found a website that offered special transformation costumes. A frog man is the next best thing they offered. I wasn't sure if it was a scam, but I had to try. And you look amazing."
Looking your body over you see the change is essentially complete. Your skin is green and rubbery from the neck down, except your chest area and the webbing on your feet which are orange. Even your penis is green and seems larger than normal, and your balls seem to have retreated into your body somehow. Having watched your transformation, your girlfriend comes closer and puts her hands on your skin. You put your hands on her breasts and she softly moans. You fondle her breasts with your webbed hands as her hands roam all over your body until finally taking hold of your cock and stroking it, but you've already gotten quite hard.
"I want your big green dick inside me! Fuck me, you sexy frog man!"
You lift your girlfriend up, feeling stronger than normal. She wraps her legs around you and slides onto you. You pin her against the wall and the two of you kiss passionately as you thrust into her under the shower. Soon she's moaning with pleasure and screaming "Yes! Yes!" You feel her orgasm but she insists you keep going and soon she orgasms again and again. Her orgasms finally get you off as well and you have to let her down at that point. You both collapse on the floor of the shower, panting heavily. Your girlfriend has the most content look on her face imaginable.