I didn't start dating until college and my first few girlfriends and dates didn't progress to sex. More often than not, I was 'friend-zoned' by so many women with whom I was interested in dating. Eventually I did form a very close platonic relationship with an attractive woman. We spent a lot of time together and some people thought we were actually a couple!
After about a year of friendship she crashed on my couch one night, and as I pulled a blanket over her I gave her a hug (which was normal for us) but also kissed her on the lips. There was no rejection, just a smile, so I kissed her again, and again, and then things really heated up quite quickly!
Caressing and fondling her breasts quickly changed course when she lifted her shirt and bra so I could suck on her breasts, and undid her pants and asked me to finger her, which I gladly did. My pants got unzipped and dropped at some point, and she started stroking my very hard cock. Since she was at the end of her period, we eventually stopped (after I got her off) and we snuggled up and went to sleep together.
The next morning, I of course woke up to a raging hard-on which she then took into her mouth, commenting on how huge I was. She then said 'If only" and I said "if only what?", and, "I do have condoms". She smiled, I grabbed a condom, put it on, and proceeded to have intercourse for the first time of many hundreds of times with her.