Emma wants to surprise you

"I can't tell you, John, it's a secret!" Emma tells you.

"Oh, so now you think you can keep secrets from me," you say surprised by your girlfriend's answer.

"I'll tell you if you want... but maybe, maybe if I could arrange something special for you the surprise would make it all more worthwhile," Emma proposes as you fuck her.

Then Emma quiets down - deep in thought either just letting the fantasy run out in her mind or perhaps scheming about how to make it a reality. Soon enough, the fantasy (along with your dick) is enough to make Emma cum. Shortly after you inseminate her with a load of your thick cream.