Gross stories???

my girlfriend called me yesterday and told me to tell her a story. I started making up a dog sory and she laughed and said, "no a dirty story" i got nervous and started telling a fake story and i got really nervous when her breathing pattern changed and she started exhaling a lot more and at the end of the story she let out a moan that ive never heard her do, and she said, "ohh, thank you" i act weird around her now. should I?