They can't resist it anymore

Slowly, the kiss unravels into something more. Their hands grope eachother trying to undress eachother untill they are both kissing naked. Elsa's cock is pressed up against Annas dripping pussy. They slowly break away from the kiss.

Anna bends down and begins to suck Elsa's cock, it only takes a few seconds before Elsa cums, releasing a huge jet of cum inside Anna's mouth wich she swallows greedily before standing back up and pushing Elsa onto the bed. She climbs on top of her sister and slams her pussy down on Elsa's throbbing cock.

Elsa: wait Anna stop, i could get you pregnant

Anna: It's ok, im on birth controll. You can cum as much as you want inside me

These words send Elsa wild as she sprays load after load inside Anna, she cums so mich that it causes Anna's belly to bloat and swell outwards. After 30 minutes of this Anna's belly is the size of an over inflated beach ball and Elsa's cock finally goes flaccid. They both kiss again passionately. Before Elsa pulls away.

Elsa: umm Anna, theres no easy way to explain this but ummm. Earlier before you came in my erection wasn't going away so I decided to try and fuck myself, I bent my cock into my vagina and when I needed to cum I pulled it out but after about half an hour, my cock had swelled so much from the constant throbbing that I couldn't pull it out, I came so much inside myself and when I finally got my cock out, the cum was stuck inside me. I think I've... Impregnated myself.

Elsa begins to cry.

Anna: It's ok Elsa, We should take you to a doctor to see if they can do anything about it.

Elsa: no, I don't want anyone to know, I will shut myself away until I have had the child and then I can come back out of my shell again, If it's okay with you, I would like you to be my childs second mother and help to take care of me and my child.

Anna: oh of course, I would love that. Don't worry Elsa, we will get through this together.

They both fall asleep next to eachother