Yes
I have done all 3. When my lover wants to watch big turn on. First time in front of a guy was when jerking after a party when a guy walked in and watched so continued. First time in front of stranger, girlfriend had a girlfriend over I didnt know. We played game made bets I lost. Told me jerk for her.
I had a g/f who introduced me to it. As she blew me, worked her finger in, found my prostate and gave me most explosive orgasm ever. She loved it as well as I. Got to point that she would tie me up tease and stroke me was intense. Ended up using prostate toy and gave me 3 orgasms. Miss her.
I had a couple played with few times. About the 3rd time playing, he went down sucking me. She watched and came twice, seeing how hot she got from it turned me on more.
Years later playing with another couple, she was sucking him as I fucked her, she held his cock and asked me to suck it. The look in her eye was hot. As I sucked him looking in her eye, she squirted all over my cock. Such a turn on.
Woke up at my gf house. Went down stairs and her and her friend was talking over coffee. I sat down and about the end of my cup, my gf asked if I would go down on her friend. After some discussion that wasn't a joke, we adjourned into the living room. My gf directed and watched as I gave her friend multiple orgasms with my mouth.