Yesterday!
Mistress bought a wooden chair specifically for tying me to. She started with a butterfly sleeve, then pulled me back and made me sit down on the chair. She pulled my wrists up, forcing me to lean forward, then pulled me back again so my arms went over the back of the chair behind me, can and then She tied my wrists off to the back of the chair. She then tied ropes around my ankles, pulling each up off the floor and tying them so they stayed there.
Then She got to work. She whacked me some with a leather strap, and when She started going after my balls I tried to close my legs to hide and protect them (even though I knew what would result from my attempts).
She responded by tying rope around first my left knee, then taking it behind the back of the chair to my other knee, and pulled it tight to force me to keep my legs spread. She added more ropes on my wrists to really make sure I couldn't get them out, and then put a loop of rope under my balls, behind the ring of my chastity cage, and pulled and tied it up behind my neck, which held my balls completely exposed and defenseless with nothing to interfere with Her ministrations.
It was enough, for sure. I could barely budge, and there wasn't a thing I could do to protect myself. She grabbed a couple of little canes and for back to it. They're fairly light canes but balls are really sensitive! She went after my thighs too, and my nipples, then grabbed a pair of xylophone mallets and went after my balls some more.
What was the best and worst was that it just made me crazy horny. I grinded and humped air, I struggled and authentically begged Her to take the cage off and give me an orgasm, but it only made Her laugh and go after my balls more.
Anyway when She'd decided I'd had enough for a bit, She put on an old Elvis movie and we watched it. She came over occasionally to make me eat popcorn and laugh at me when I couldn't stop it from falling on the floor. And whenever a song came on, She came over to gleefully drum along on me!
She let me out when the movie was almost over, I think I was probably bound for about an hour and 45 minutes which was enough. It was really great though, I never lost feeling or circulation, and it was SO MUCH FUN!
Apparently we may be making this a semi-regular thing. There's plenty more corny old movies to watch, after all

Male slave in Victoria, BC - collared, in chastity, and married to my Magnificent Mistress.