The first time my boy fucked me I had no idea about the knot. I was laying back with my ass propped up on some pillows so he could fuck me missionary. He was standing between my legs which I had spread high and wide, and as I started jerking him off I just let him thrust forward and find my hole. As soon as he found it, he started humping like mad and I let go of him and let him take over. He fucked me so deep and hard that he rolled me up onto my shoulders, pinned down and unable to react even if I knew what was going on. My eyes just rolled up into my head and I started cumming like crazy. When he was finished humping me I felt so nasty and full of cock. I could not believe what I had just done. I was covered in my own cum but still hard as a rock so I stroked myself to another powerful orgasm as he stood over me, drooling, panting and pumping me full of his cum. After a couple of minutes I was getting uncomfortable in this position so I thought it was time to push him off of me and get his cock out of my ass. I realized that he was stuck in me and I had no idea why, so I panicked. I pushed him off and he pulled out of me with a loud pop. I immediately felt pain like never before and jumped up as liquid poured out of me. I thought it was blood and some of it was, but most of it was cum. I was in pain for days from that but fortunately I healed up. When I realized what had happened and why, I knew that if I was ever to do that again, I would need to give him enough time to shrink before letting him pull out. After a couple months, I got up the nerve to try again. I came just as hard, waited him out for about 15 minutes and he was able to pop out with no problem. We only ever fucked when I knew my parents would be away for the whole day so we could tie for as long as it took. If I wanted him in me but didn't have time for a tie, I'd suck him off then have him lie on his back so I could ride his cock and jerk off. I've since learned that dildogging is not well accepted but at the time I didn't see anything wrong with it. He was still filling me with his cum so I thought he liked it as much as I did.