She stiffened as her climax overcame her and she'd learned to squirt her cum long ago so she filled my mouth with delicious nectar.As she hit her orga...m, she cried out, "Aaaaah!" It was pretty loud for 1:00 in the morning so I stopped licking and grabbed her head. "Shh!" I whispered, afraid that she had awakened out parents. "Hold still a moment!"We held still in that position for a moment but she laughed and wiggled her pussy in my face then began sucking on my throbbing boner again. I tried. The perfectly round pink middle peaks stuck out like rubber erasers, longing for attention. I wanted to taste them, run my tongue over her nipples until she moaned with desire. Yes, I knew that it was wrong having a girlfriend, but what my best friend’s sister was doing now was also wrong because she knew it as well.Still, I was enjoying every minute of what was happening. My hand was still wrapped around my cock as she moved closer towards me and I suddenly wished that it was her perfectly. The tank I’m driving was in her garage with twenty-two hundred miles on it. She really did only drive it to the store and church. Her mechanic would wait for her at church, help her inside and then do a full detailing on it after checking it over for any leaks, rust, or other problems. It is from the seventies so it even has an antique plate on it. Since it was made to run on lead gas I must put in this expensive additive and it gets maybe five miles to the gallon. That is just enough to come. I thought to myself,"hmmm, things could get interesting tonight". Later, after we had a bite of food and a couple of drinks it was time to go see Grandma and Grandpa. They had a big day of activities planned for our son the next couple of days and had asked if he could just stay with them for a couple of nights. Marin said she felt tiered and asked if I could go drop him off while she had a nap. I didn't like the sound of her going to bed, there was a strong possibility that she'd be down for.