How to keep it interesting for a gemini?

I am a pisces male and I currently dating a gemini. Sometimes we have good conversation that can last a long time, and sometimes i just don't know what to say because i feel akward. Also when we have a conversation going sometimes she messes it up when she gets sarcastic and it just dampens my mood. I understand that's how geminis are so I try not to let it get to me. But any gemini women or anyone have things I should talk about with her to keep our conversation alive? Or also what can I do in the relationship to keep her into me