I experienced this, but it wasn't exactly my choice. My current boyfriend and I have been dating for almost 2 years now. When we first started dating, I noticed he definitely had some alpha-type tendencies (several times, he literally ripped my underwear open to get to my hole). Our sex was definitely some of the best I've ever had. We ended up moving in together, and we would fuck nonstop. I was still a hungry cumdump sometimes though, and one day my boyfriend found out. Long story short, my hole was already filled with someone's load one time when he went to fuck me. He laughed it off and said he thought it was really hot. Over the next few days, he started talking about how we should open up our sex life and have threesomes, etc. We had been getting kinky in the bedroom already and this seemed really hot.
We had a really hot friend who was a hung dominant top kinda guy, so we hit him up. My boyfriend had the idea of getting a hotel room, and they could just hang out and fuck me all day. We got the room, and the other guy met up with us. We played around for a bit, when my BF pulled out some rope and said it would be even hotter if they tied me up - and it was. I was on my knees, hands tied, feet spread, as they went back and forth between using my holes. I was sucking my boyfriend's big cock as he watched our friend pound my hole, telling me how hot it was to see other guys use my cunt. Eventually, they both blew their loads and sat in the chairs drinking beers, leaving me tied up on the bed as they bro'd out.
Then, after a few drinks, my boyfriend laughs and says to me "So, you wanna be a cumdump huh? Going around my back getting fucked by god knows how many dudes? Such a cock hungry faggot, can't go a few hours without a man's cock in your little pussy. Well, let's make you a real cumdump haha." I was facing the opposite direction from them, unable to see their faces, my cum soaked ass pointed towards them. Then, I hear them get up and then the door close. They left. I laid there for almost 30 minutes wondering what they were doing, when they were coming back, when the door opened. It wasn't them. Some random guy just walks in, rubs his cock along my already cum covered hole, and started pounding me. He blew his load in my hole, pulled up his pants, and left. This went on all night, random guys just walking in, making comments about my hole or whatever, and breeding me. Sometimes it would be 2-3 guys at a time. One of them had what had to have been an 11" cock, and he pounded out my hole relentlessly. It became harder and harder to even feel each subsequent cock, and they began commenting on my "sloppy loose pussy". I didn't know how to feel, but a part of me was enjoying every second. Eventually, after probably 6 hours, my boyfriend and our friend returned. They laughed and made some remarks about the condition of my hole at that point. Although I didn't know what to think at first, my boyfriend knew I learned to love it. He even started fisting me (something he'd never been able to do before), just to prove a point. And that was the night. True story. My boyfriend has become even more of an alpha top kinda guy, and it's amazing.