That happened to me one time. We used lube we never used before. I had the head of my cock pressed against her hole. I shifted forward to position myself to enter her slowly but the head popped in and slid deep inside. Caught me by surprise how fast it happened. She yelped and yelled too fast. Afterwards, she told me I really hurt her and caused a little bleeding. I felt so bad. Never used that stuff again and made sure to be extra careful. Now, years later I know what it's like to be entered too quickly and can appreciate how she felt.
My first time being anally fucked was with a gay friend, Bill, I ran into one night at our local pub. We each had a couple of beers before he asked me if I wanted to go to his apartment to smoke a joint, an invitation I did not refuse. Sitting together on the sofa after getting stoned, he asked if i had ever had sex with a man? I told him about beating off with a few friends when I was in high school. He then told me he would love to introduce me to the joy of anal sex. Bill was amazingly gentle knowing that it was my first time. He gently lubed my ass sliding one finger in gently. He probed around and found my prostate which was amazing. He added two more fingers one at a time and asked me if I still wanted him to fuck me. Yes! I told him. We undressed and he had me to lie prone on the bed with a pillow under my hips, then fingered my ass another minute or so, then shifted and pushed the mushroom head against my hole. It was really tight and my friend told me to breathe gently and push like I’m taking a shit. Suddenly Bill’s cock head pushed through my sphincter and he began slowly thrusting in and out. Being stoned heightened the amazing sensations of pain and pleasure from his cock fucking me. He started thrusting harder as he neared ejaculation. Feeling his cock pulsing inside me as his cum filled my ass trigged my huge ejaculation that actually surprised me. I was so attune to Bill’s fervor and the heat of his dick thrusting inside me. That was my first hands free orgasm. It left a big puddle on the pillow case.
Wow, that's a great story. You are very fortunate to have had such an experienced and compassionate man to introduce you to the joy of gay sex. Hopefully you have been able to "pay it forward" on his behalf.