Go see a play. Sit in the back and make out. Go to a water park. Make out in the backseat of your car.
When I was twenty eight my niece fixed me up on a date with her best girlfriend and before midnight camewe were back at my place fucking like two dogs in heat. She told my niece how good I fucked her with my larger than average cock and a few days later my niece and her girlfriend dropped by unannounced. We drank some wine ,smoked a little pop and at the urging of my nieceI played a porn vid for them. We all ended up in on my bed naked and thats when I found out my niece was bi and had been since she was fourteen.