Another naughty fantasy has to do with this one particular ex of mine. She was unbearably ticklish, so much so that she never really let me tickle her at all, because it was excruciating torture for her. One time, she let me pin her arms back and tickle her tummy, sides, and armpits for about ten seconds, and she was just shrieking with hysterical laughter, desperately shaking back and forth as hard as she could. It was insanely hot, but also so frustrating, because I never got to tie her down and just really go to work on her.
We only dated for a couple months, because she had to move to another city for work, but we kept chatting. And sometimes, we would get really flirty, borderline sexting, and she would tease me about just how ticklish she was, knowing just how bad that was going to wreck me. She also regularly posts lots of teasy pictures on IG, stuff like her in a sports bra with her arm up in the air, completely exposing her unbearably ticklish tummy and underarms. It just wrecks me.
So... obviously, I fantasize all the time about getting her at my mercy, stripping her naked, and stretching her out and tying her down tight. Like, a really intense set up, where she not just has her limbs spread out and tied down, but straps around her thighs and upper arms as well, because like I said, she's unbearably squirmy. Then, I'd spend several minutes straddling her body, just wiggling my fingers in the air, inches from her skin. I would remind her how bad she teased me, how she just loooooved to get my tickle lust going when she thought I couldn't do anything about it, and ask her if she thinks she deserves to be punished for that. She would know there's nothing she could do to convince me otherwise, but she'd still desperately beg for me to please, please not tickle her. That she's sorry, that she'll do anything, that she knows she deserves it, but she's seriously SO ticklish, she won't be able to stand it...
And then, of course, I'd submit her to the worst tickle torture she could ever imagine. I'd just continually move my hands around her tummy, sides, underarms, breasts, tickling all over, non-stop, probing for the most ticklish spots and focusing right on them. All the while teasing her about how helpless she is, making her admit that she's a naughty tickle tease, that she deserves to be punished. Every few minutes I might briefly stop, hovering my hands just inches from her underarms, giving her another chance to beg me to stop tickling, to convince me JUST how ticklish she is, giving her the faintest spark of hope that I might stop... and then I'd just go back to torturing her.