My first sexual intercourse experience was with a 32 year-old woman-friend who was having her period. I was 17 years old at the time. We were both in bathing suits at her house. I was a lifeguard at a nearby swimming pool, and she treated some of us to food at her house during our breaks from lifeguarding.
She had been flirting with me for some time, and we found ourselves alone at her house. We started kissing, fondling each other, and eventually we took off our bathing suits. She proceeded to pull out her tampon, which was a little stained with her menstrual blood. I started rubbing my erect penis up-and-down her vaginal slit, and gradually entered her. We stroked a few times like that, and then she went on all 4's, while I got behind her and entered her again doggie-style.
LOL, it didn't take me long to cum inside of her! The sensation of her slippery vaginal fluids mixed with the texture of her menstrual blood was too much for me to resist my orgasm! When I pulled out of her, my penis was coated with a mixture of my cum, her vaginal juices and her blood.
There was no time for cleanup as I had to get back to the pool for my next shift, so I just put my bathing suit back on as my erection continued to subside. I was feeling wet inside my bathing suit from our mixture of vaginal juices, cum, and menstrual blood! This was my “Summer of 42” experience, which has lasted me a lifetime…..I'm now 67 years-old, and am grateful for having had that amazing experience!