You tried.

"Sofia I don't think I can" you say as you feel it building. "Please I am close its right there its getting there" she says. As her orgasm hits, it causes her pussy to lock down onto your cock as the head hits right at the womb. Feeling the pressure tips you over the edge. "Oh god I am cumming. I am cumming in your pussy." you say as you paint her womb in your seed.

You both come down from your orgasm's. You cuddle for a few when you tell her the problem. "Sofia I have cum in you. Do you know what that means?" you ask. Sofia looks lovingly at you and says "yes that mean i have a 50/50 chance of being pregnant with your child". You look at her and don't know what to say.

A few weeks later she comes to you and tells you that she is differently pregnant with your child and that she can't see you anymore. Afraid people will find out the truth and you would get into trouble.