It was mid-summer and my family decided to go for a week to our summer house in the beach. At that time my girlfriend and I had almost 1 month of dating; she is a beautiful blonde well-fitted girl, with dirty blonde hair, 5’5 perfectly well shaped 34-B breasts and a well-rounded ass, with beautiful toned legs, and amazing blue eyes… I asked my parents if my gf could tag along with us; which they agreed. I was 18 and she was 17… for obvious reasons my girlfriendf stayed in a bedroom with my little sister, and I stayed in a separate room with my 2 brothers. We spent a lot in the pool and going in and out into the ocean. My brothers had spent all day on our waverunner, so I told them it was my turn… we hopped on the wave runner, I took the steering wheel and my gf sat behind me and wrapped her hands around me. We went for almost 2 miles deep into the ocean, and she started to move her hands down into my bathing suit. I felt a little tremble and immediately I could feel my cock getting hard; her hand reach my now hard cock and started to stroke it slowly. I was getting really horny, so I stopped look back and I could see the beach far away. So, I turned around face to face with my girl and started kissing her with such passion and hotness, my hands reach her back and found the knot tied of her bikini, so I pulled the knot realising her bikini, exposing her perfectly rounded perky breasts.