[MF] my gf sucked me off in the backseat while her hot sister drove

This is a true story about my gf from a few years ago, I’ve changed names and some other small stuff but ages and physical descriptions are true for the time.

A couple months into our relationship, my [20M] gf[19F] Jess and her whole family went on a family vacation for a couple weeks. We were still in our honeymoon phase and would fuck as often as we could. These two weeks would be the longest we’d have gone without fucking since we started dating. Jess had a very petite figure. She was about 5’3” with a tight ass and small but perky boobs. Her face was beautiful though, and her best feature was definitely her plump lips which she loved to wrap around my dick. Jess had an older sister Nina [24F]. Nina looked a lot like Jess but she was slightly taller and had a thicker curvier figure. I’ve always found Jess’ face more sexy but even though Nina had a killer body, she had a cute innocent face. I’d be lying if I said I’d never fantasized about her, even while fucking Jess.