Not well at first.

The girl did panic but the 2 of you managed to calm her down. Hiccup promised to fly her back to your home island once he's mastered flying Toothless. Until then she'll hide in the hole with toothless.

Despite there being humans hear, you still decide to live on Berk. You and Change Tail scout the island and find a noinhabitated cave far away from the village. You decide to move in.

Time passes. Hiccup teaches you the tricks he learned while spending time with Toothless. He also spends alot of time with the girl. When he finally mastered riding Toothless, he started flying her home. However half way there she confessed her love for Hiccup and they flew back.

Change Tail was irrated at first. She wanted that girl to join your harem afterall. However then she saw an opportunity. The opportunity to add a Night Fury to your harem instead. She squirted a bit of Jelly into Toothless's mouth while Hiccup was away. Toothless was mad for about 2 seconds until they realized how nice it tasted. Change then fed Toothless enough jelly to turn Toothless into a futanari.

The next day you wake up with a stretch. Your surprised Change didn't wake you up by licking your cock like normal. "Morning my love. Not horny this morning? Thats a first." She cuddles up to you but doesn't do anything sexual. You find it odd but shrug.

You ride her to the hole to say good morning to Toothless and Hiccup's girlfriend Brynhild. Soon after Hiccup arives. You go to him. "Hey man. How was hunting training?" He sighs. "Top of the class, again. Also my dad said he was proud of me." You can tell by his tone he's not happy about this. "You got everything you've ever wanted, only after you don't want it anymore. I get it. Also unless you want to kill a dragon for real, your going to have to end this lie eventually."

He gets agitated. "I'm the cheifs son. I can't just move to a new island and live my life a hermit in the woods like you." Brynhild comforts him. "We'll figure something out." She snuggles him.

You decide to do a bit of training, balancing on Change Tail as she runs at full speed. You've improved alot since you started your training. Once you're back from your practice ride, Hiccup decides it time to start training proper. "OK, no more moping. Time to get to work. Today you'll be training how to keep flying at full speed while avoiding obstacles. I'll show you how on, lets go Tooth- what the fuck!?"

He sees a vagina underneath Toothless's sheath. "What happed to my dragon?" You notice your dragon turn purple. "Change, did you turn Toothless into a futa?" She chuckles cheekily. You sigh. "I at least hope you didn't **** Toothless to do so." You look at Hiccup's dragon. She doesn't seem to mind the sex change.

Hiccup regains his composure. "Well, lets see if this chage has affected Toothless's flying in any way." You go for a fly with Hiccup before training. Toothless turning into a futa hasn't affected her flying at all. So you start your training. Its a bit hard at first, but since Change Tail isn't the fastest flyer, you have a larger margin for error then Hiccup and Toothless has. It soon becomes dusk. Hiccups flys closer to you. "The dragons seems tired. Lets call it quits for the day." You nod and start flying back to the hideout.

Hiccup looks at you. "Your learning fast. I think with a little more practice you'll be just as good at flying as me." You give a thumbs up. "I had a good teacher." You arive at the hole. Hiccup and his girlfriend leave for a date. However instead of heading home like usual, you stay with Toothless. You know full well why Change Tail did this. However the book has very little information on Night Furies.