Be VERY CAREFUL when responding to this thread as anything that even suggests that it happened before you were 18 is against the site's policies.
So far, everyone is playing by the rules, as will I.
My first time I was over 18, as I got a late start in dating.
Some kissing on the couch lead to me caressing and fondling her breasts above her shirt, then she pulled her shirt and bra up so I had skin access. I started kissing her nipples while cupping and fondling her breasts, which caused lots of moans of pleasure from her, and kept me as hard as a rock (in my pants). She then unbuttoned her jeans, laid back pulled them down along with her panties, and asked me to finger her. I happily did just that while also continuing to cup a breast and suck on a nipple.
While fingering her, she had fondled my crotch, so I unbuckled my belt, unzipped my jeans, and dropped my pants and underwear down so my raging erection was finally free. Feeling someone else stroking my cock (other than me) felt amazing!. I continued to finger her, inserting up to 3 fingers inside her, until she came.
After a minute of recovery I asked her if she would go down on me. She said "of course!" and we switched places on the couch, so I was reclining and she had full access to my still very hard cock. She started stroking me and then taking me into her mouth. I'm 7" by 6" and she could get about 3-4 inches of me inside her mouth. Using her lips and tongue on me felt simply amazing. After just a few minutes she stopped, looked up at me while still holding my cock, and said "You're huge!" . That was a huge compliment and got me just a little bit harder. I said "Really?" and she said "Yes, you're one of the biggest I've ever had".
While looking at me with lust in her eyes, she then said "If only". I said "If only what?" She said "If only you had a condom!" I said "I do!" and retrieved one. Even though I was a virgin, I wanted to know how to use condoms and sometimes used them for masturbation so I could cum when I wanted without making a mess that needed to be cleaned up.
I came back to her with condom in hand, put it on, and she laid back on the couch and spread her legs. I climbed on top and did have some difficulty in inserting myself into her as it was a deep seating couch and we both sank into the cushions. We had a laugh about that and moved to the floor. I was then able to insert myself in her and finally experienced the absolute joy of intercourse. We changed positions so she was on top riding me.
I fell in love with cowgirl right then in there as a pair of beautiful breasts were right in my face, while I could put my hand on her hips and ass to help her ride up and down on my cock. I took advantage of using my mouth, hands and cock on her all at the same time, and after a bit I felt myself building towards orgasm. I thrust deeper and deeper into her while she bounced up and down on me as I then exploded in orgasm. We both just stayed wrapped together with her lying on my chest until we both caught or breath.
Obviously I remember a lot about my first time, it was simply amazing, something I been craving for a while. It was a life-changing experience for me, as now I wanted to have sex or make love all the time, every opportunity I could get! Thousands of sexual sessions later, I still have those incredible feelings like I did the first time, enjoying every aspect of making love, and when it comes to intercourse, every thrust in, every stroke (almost) out and every moan of pleasure from me and my partner, and every orgasm have been wonderful experiences.