I (M23) finally got to live out a fantasy of mine! My domme fiancee (F22) said for quite some time that pegging was a hard no. Even though it was a big fantasy of mine, I accepted this. Then 2 months ago she said she'd try it but to not expect her to like it. I was disappointed hoping she'd go in with an open mind, but she was finally at least willing to try. Last night we went out to a bar with a bunch of friends and she and I have a lot to drink, but she got really drunk. She is a really horny drunk and after a fair amount of teasing a friend drove us home. We stripped and started making out as soon as we got in the bedroom. She told me she had a surprise for her good boy. She told me to put on my collar and to lie on the bed. Knowing it was a personal favorite, she sat on my face. I love happily lapping away and hearing her moans of pleasure as she grinds on my tongue. After eating her out for a while, she got off and asked if I was ready for my surprise. She instructed me to get out the strap on and to put it on her. My heart was racing and I couldn't get to the toy box fast enough. On my knees, I helped her slip on the harness. After securing the straps, she grabbed the back of my hair and told me to suck it. I had never seen this side of her and I wasn't gonna stop it. As I got to work she asked, "how do you feel that Mommy's cock is bigger than yours?" I was in sub heaven. I told her I was so lucky and got back to sucking. She pulled me off her cock by my hair and I begged her to fuck me. She told me that was enough and to lube myself up. I got on my hands and knees and presented myself, face down ass up. "Good pet," she cooed. When she penetrated me it was pure bliss. It was the moment I have dreamt of for so long. Every thrust was magical. She got into a steady rhythm before saying, "fuck I think I might like this." She buried it in me and said that I was Mommy's good boy. When I was getting close, she pulled out and switched to a smaller oral dildo and told me to I was to cum on her cock and to suck it off, to which I happily obeyed. Everything was so hot and I loved every moment of it. I look forward to even more in the future and I hope you all enjoyed my first steps into pegging!

Edit* forgot to mention that we switched dildos at the end.