Start by telling her how cold the weather is and tell her that you're under the blanket and all you could now wish for is someone to cuddle with!
If she says, me too, there you go bingo !
If she doesn't, ask her, if she would you care to join you ;)
That must act as a good start and you may gear up as the situation requires ;)
If she clearly expresses her disapproval, stop. And find a new one :P
At all times ,keep it cool and try not to sound desperate, take it slow and In a little bit of time ,you're sure to be where you wanted to be !;) Visit this sexting site to read relevant content.
You can start with this joke :
John: Grandpa do you still have sex with granny?
Grandpa: Yes, but only oral.
John: What is oral?
Grandpa: I say Fuck you, and she says: Fuck you too!
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After the joke you can just playfully say fuck you with laughing emoticons .... If she replies fuck you too... Congrats !! You get a green signal ;) then maybe you can start by asking questions like these :
* Can I ask you a question?
* Do you fantasize me?
Want to sext with a girl?