I have - when I was much younger and more limber (and longer). I definitely wish I still could.

I was 25 when I let an older coworker talk me into stripping for him, then letting him jack me off. The next thing I knew, I was letting him watch me shower and jack off for him while he jacked off. Within just a couple weeks, I was stripping the minute I walked into his house and he was swallowing my cum like he lived on it. He was the first person to suck me to an orgasm, the first to swallow my cum, and the first to lick my ass hole. He was the first man I ever kissed and his was the first cock I ever tasted.
I was 25 when I let an older coworker talk me into stripping for him, then letting him jack me off. The next thing I knew, I was letting him watch me shower and jack off for him while he jacked off. Within just a couple weeks, I was stripping the minute I walked into his house and he was swallowing my cum like he lived on it. He was the first person to suck me to an orgasm, the first to swallow my cum, and the first to lick my ass hole. He was the first man I ever kissed and his was the first cock I ever tasted.
Once upon a time I was banging a guy at work. Does that count? I said nothing. My boss eventually figured it out. Actually, he was jealous because he wanted to get with my lover. It didn't matter, though. Neither my lover or I cared about boundaries or exclusivity, even though I couldn't stand my boss. I loved my lover and how he handled my cock.
I'd do anything she asked. If she wanted to see me with another man, she already knows I've done it before. And, she knows I don't mind being watched. She also knows I'd be down to let a man have my ass while she sucked my cock. She doesn't even have to dangle the carrot of seeing her with another woman in front of me. I might like that. But, I'm more interested in fulfilling her fantasies -- especially if they include me with another man.
I've answered this before in other threads. Yes, I have. When I was much younger, I was enticed into an fwb relationship with an older coworker who made me feel like a supermodel. I mostly received, but occasionally gave. I wouldn't do it again. But, I wish I'd been more open and adventurous at the time.
It's been a long time. But, when I was a slave, one of my masters liked a cat-o-nine-tails. He used it on me often just to establish our relationship. It was rarely about discipline. It was about his desire to establish and maintain his dominance. And, it wasn't light and playful like you see on tv or in movies. Daddy was intentional and painful. I felt every lash and had the scars to prove it. But, Daddy was generous. I was allowed to make him cum for every whipping I received. And, I loved every minute of it.
I used to love being restrained and controlled. I loved just dropping to my knees before my masters and giving myself over to their desires. I was happiest when they chose to tie me up and use me in various ways, especially when they shared me with other masters.
My favorite thing was being tied over a table or something like a pommel horse and being used from both ends at the same time with no way to move or pull away. For several years, I couldn't get enough of being filled with cum from both ends.
With my fwb 30 years ago, I was mostly a bedroom submissive. But, I often played the slave to my daddy throughout the day. He required me to wear cuffs and a collar in his house and nothing else. I often performed menial tasks for him. But, that was as much out of a desire to please him than anything else. I was more a sex slave than anything else.
I just turned 60 and I've never had a problem with getting an erection. I can rub my hands over my wife's body for a couple minutes and be hard as a rock. And, every morning I wake up with a stiff kickstand. My problem is injury-induced peyronies. After two unintentional pull-out errors a couple years ago, I developed a slight right lateral bend and an acute vertical/downward bend. I've been working with pumps, massage, gua sha, and vitamins/minerals ever since with some promising improvements. I'm thankful especially that I haven't had any pain associated with the peyronies, which is common, and I continue to have strong nocturnal erections and sensory-induced erections from playing with my wife.
When I was in an fwb relationship in my 20s, I wished I could deep throat my older lover. I tried practicing with a long dildo. But, I couldn't get more than an inch past the back of my mouth/throat. That only got part of Bruce's thick head into my throat. But, he was a master. He could swallow every inch of me.
I was 25 when I let an older coworker talk me into stripping for him, then letting him jack me off. The next thing I knew, I was letting him watch me shower and jack off for him while he jacked off. Within just a couple weeks, I was stripping the minute I walked into his house and he was swallowing my cum like he lived on it. He was the first person to suck me to an orgasm, the first to swallow my cum, and the first to lick my ass hole. He was the first man I ever kissed and his was the first cock I ever tasted.
I was 25. He was 40. I let him watch me take a shower. I tried to be as sexy as I knew how. But, when I saw him sitting on the toilet stroking his long, thin cock, I couldn't help but begin stroking my own stiff meat. In seconds our eyes met and I licked my lips. We stroked and groped ourselves for several minutes before watching streams of cum blast across the room in opposite directions. We never let our semen hit the floor after that. Every drop was licked up and swallowed for the remainder of our relationship.
The first time I received was amazing. My fwb was hesitant. He hadn't had a virgin in thirty years. I'd prepped myself with a dildo roughly the same size as his cock. But that really did nothing to prepare me for the intensity of a live, throbbing cock pressing against my tight sphincter. The first time was intense and almost painful. But, I loved every instant, every sensation, especially the feeling of his hot cum spraying into me. I begged him to stay inside me and lay down on top of me. I wanted him to remain inside me until he was too flaccid and I pushed him out. We both jumped and gasped when that happened. But, it made me forever his bottom. For the two years we were together, I wanted nothing more than to feel his cock and cum inside me.
I came every time my fwb put his stiff cock in my ass. I tried dildos and vibrators of various sizes and shapes. But, nothing could imitate the feeling of a live, throbbing cock moving in and out of my tight hole. He didn't have to touch my cock. I was hard almost from the instant he pushed against my sphincter and exploded within a couple minutes, usually before he did.
My gay fwb had been so generous for a couple years, taking care of me and just letting me masturbate and make out with him. When I finally dropped to knees in front of him, he was shocked almost to the point of cumming too quickly. I didn't know what I was doing. But it only took a couple minutes to feel his massive explosion in my mouth. I couldn't get enough after that first time.
Well, I've confessed this several times on here including a lengthy story series. But, I once was seduced by a gay male coworker into first stripping for him, then letting him give me a handjob. I was only a couple years married at the time.
Eventually, I was letting him watch me shower and masturbate. Within a few weeks, he was sucking me to intense orgasms on a weekly basis.
In no time, we were showering together and making out in his bed.
Our mutually beneficial relationship continued for a couple years before I had to move away.
Thirty-five years ago I was in my twenties and married. An older male co-worker came on to me, flirted with me, and eventually propositioned me. He offered to pay me just to strip for him. He was desperate to see me naked. He said I looked just like his first love from high school.
After quite a bit of negotiation, I gave in and found myself at the end of his bed late one Saturday night after work. I slowly, nervously, removed my clothes, one piece at a time, to his audible, demonstrable approval.
His excitement became begging and more negotiating for me to allow him to give me a handjob.
That night turned into two years of weekly to monthly visits that found me naked the minute I walked in his door, showering for him or with him, letting him do anything he wanted to me. I came in his mouth more than I've ever cum in my wife's.
Every time I pulled into his driveway, I knew I was going to cum at least twice within the next two hours.
Moving away to a new job ended our playtime. But, I'll never forget anything we did together.
Mouth is almost definitely my favorite. But, it's been so long. My wife has only done that a couple times in almost 40 years. I had an fwb many years ago who only wanted to swallow. That was amazing. Otherwise, I've only ever cum in my wife's hand/on my stomach, inside her pussy, and once on her ass in the shower. But, cumming with her is amazing no matter where it goes.