Have you ever been walked in on while masturbating ?

Yes, many times in high school, college and since then too.

A few times, my ex use to do as a tease for sex

Not only walked in on while masturbating, but I was laying on top of the bed completely naked and the moment [removed by mod] and her friends walked in on me. I was ejaculating.

I couldn’t even hide because I was on top of the covers. [removed by mod] immediately screamed you’re disgusting but her two girlfriends had other ideas. They wanted to watch me do it again and this time I have [removed by mod] and her two girlfriend sitting around the bed watching me. I thought I would be embarrassed, but instead it got me even more horny.

Not per se. Some close calls and quick cleanups, though.

Just by my cat

I could not count the number of times - So often by my FWB - which often leads to a more satisfactory and full - filling experience.

Yes. While in the shower.