At a luxurious apartment in San Francisco, Elsa was reading a book called "Ice storm" on the couch in the living room. Elsa hears steps coming down the stairs; she turns to see her sister Anna. She wore a purple hoodie, blue legging, white socks, and white shoes.

Elsa asks Anna, "So where are you heading off too?"

"Oh I'm going to meet a friend at a diner."

"Okay."

"So are you going to read your book for the rest of the day?"

"No, I have to get work. Apparently someone thought it would be funny to mark up a dinosaur skull at the museum so I have to get head down there to find how much for the damage."

"Ah that's sucks."

"Yeah I would be at work for most of the afternoon."

"Don't worry once you get back home you'll get a nice warm dinner. I was thinking about pizza."

"That sounds nice."

"Anyway, see you later Elsa."

"Bye Anna."

Elsa goes back to her book and reads a few more chapters before going to her work and dealing with the problem.

Four hours later

Elsa returned home early in the evening after finding that dinosaurs' bone clean-up wouldn't cost that much to clean up. Elsa goes to her bedroom, changing her work clothes into a simple light blue t-shirt, white gym shorts, and dark purple socks. Elsa sat on her bed, listening to classic pop songs to unwind, and she was about to fall asleep. When one of her earbuds falls out of her, she hears two voices from the hallway.

One of the voices she recognized was her sister, "oh Hiccup."

"Hiccup?" Elsa thought, "isn't that nice boy who helped Anna and I with our car?"

Outside of Elsa's bedroom, Anna and Hiccup were making out in the hallway. As Hiccup picks up Anna off her feet, she puts her back on the wall and keeps kissing her.

Anna broke the kiss "woah your strong."

"Yeah I've been working for the past few months."

"It shows," Anna wraps her legs around Hiccup's waist and keeps kissing him.

Hiccup carries Anna to her bedroom, and she is able to open the door with her free hand, and the two get into the bedroom. Hiccup place Anna on her bed and close the door behind them,

"Are you sure your sister isn't here?" said Hiccup

"No she at work she won't be back at seven," said Anna

"Alright then." and the two continue to make out

Back in Elsa's bedroom, she couldn't believe what was going on. She wanted to come out of the room and give Anna a talk, but she didn't want to embarrass her sister in front of Hiccup.

"I'll just wait until they're done kissing and let them have a moment then I'll go in there," Elsa thought. Then she heard her sister moan, "what the-"

Meanwhile, Anna was in her bra and on her knees on the floor with Hiccup holding her head as she saw a large bulge in Hiccup pants. He takes off his pants then his underwear to reveal his large dick.

Anna was in a trance, but she managed to say to him, "I never get tired of seeing your dick Hiccup."

"Good," Hiccup rubs his dick on Anna's cheeks and lips until Anna opens her mouth, giving him a blow job.

Anna manages to take Hiccup's cock down her throat and try not to gage. Hiccup then starts to throat fuck Anna thrusting in and out of Anna's mouth. Hearing a moan while taking his cock made him much hornier until he felt he was about to cum.

"I'm about to cum. Take it all Anna." said Hiccup.

Hiccup cums into Anna's mouth and does not letting go of her head until he feels there is nothing left and he takes his cock out of her mouth and lets her catch her breath.

"I hope it wasn't too rough Anna?" said Hiccup

"No I'm good," said Anna

"Okay," Hiccup kisses on her forehead, "now since you pleasure me I'll pleasure you."

Hiccup puts Anna on her stomach. He takes off her pants and her wet panties. Then he starts to eat her out, placing his right hand firmly on Anna's ass.

"Hiccup, you're so good!" Anna shouts

Elsa, meanwhile, tries to drown out the sex through her music, but she starts to reach down to her shorts, and she starts to play herself and imagine what's going in her sister's room.

"Hiccup must be an incredible lover," Elsa thought as she tried not to moan and kept playing with her pussy and biting her lower lips.

In her sister's room, one slaps Anna's ass, and Hiccup sticks his tongue into Anna's pussy, and she cums.

Anna weakly flips back over and looks at Hiccup "you know your talk about dragons makes me think you have the tongue of a dragon."

"Thanks I guess," said Hiccup

Anna looks to see Hiccup's dick gets hard again and smiles. "I think mini Hiccup is ready for action again."

"He sure is." Hiccup goes to his pants and takes out a condom, and puts it on.

Hiccup takes Anna on the edge of the bed, sits on his lap as she grinds on Hiccup's cock, getting her pussy wet, and he inserts his dick into her pussy. Start fucking. The two have sex likes it's no tomorrow. As he gropes Anna's ass for a while, they lock lips. At the same time, Elsa kept masturbating and rub her breast, not listening to her music but her sister's sex.

"God they keep this up I'm going to cum." Elsa thought

The two lovers changed their position to missionaries, and both of them felt they were reaching climax.

"I'm going cum Anna." said Hiccup

"Same Hiccup let's cum together." said Anna

With one last thrust, Hiccup and Anna cums together. Hiccup looks into Anna's eyes and gives her one last tender kiss before they fall asleep with each other's arms.

Forty minutes later

Elsa comes out of her bedroom feeling flush on what she did and tries to go downstairs. However, coming out of Anna's bedroom was Hiccup in his shirt and underwear, and they both awkwardly stared at each other.

"This is embarrassing," Hiccup thought.

"I have no idea what to say," Elsa thought, then he saw Hiccup looking down and saw her Elsa wet short "oh fuck."