1. He's fairly skinny, so what is the best position for hard paddling and caning without hitting his bones? We're both used to paddlings in school annd would like to replicate it as safely as possible
Striking against his bone will hurt him for sure, but what you need to be more careful of is organs - the kidneys in particular are vulnerable to spanking. Start of on his butt - aim for 7 strikes to the glutes, 2 to the top of the legs where they meet the glutes, and one either slightly above teh glute, or midway down the leg.
2. I don't wear heels but I've heard it can hurt feet after a while. Can I use this as a punishment by telling him to wear them for certain time? I am already taller than him and this makes our roleplays quite natural at the same time so I hope him on heels don't make this effect disappear.
Sure you can use punishment of heel wearing - how you maintain dominance isn't all about height - you could tell him he looks girly, or criticise the way he walks in them for example
3. Is it safe to slap him? Not talking about real female-anger slaps ;
Why do you think it would be unsafe?
4. What is the best way to pinch his nipples? We've tried clothes peg but they keep coming off!!! I think the tip is the most sensitive place but the area there is so small
Nothing beats biting in my experiencce, but there come bloody close... https://www.lovehoney.co.uk/product.cfm?p=29731
5. Why do different canes of the same diameter have different sensations? His feedback was the LH wrapped cane gives deeper pain while the one I got for him while traveling in India (supposedly the real ones still used by parents) is more on the surface. In fact, the LH cane is hardly flexible but I can easily bend the Indian cane.
You're scrathcing teh surface of teh answer in your question - diameter isn't the only thing that causes the sensation - weight, flexibility and material all have influence. Inflexibility means more of teh force of the cane transfers to the skin, whereas with a bend some energy is lost in the bend. You can use this against him by flicking it rather than striking with it. Flexible = flick, inflexible = whack. It's actually a lot of fun experiementing with different canes, and when he really wants a hard heavy thud, you can tease him with the lighter ones.
6. I've read that some schools in the world still use punishments on hand palms but supposedly this can be unsafe. Is this true? Any other options for some real pain? ;)
I don't know if it's unsafe - the hands are hardy, have tought skin and can take a lot of punishment, but there is a lot of tendons, blood vessels and nerves in there.
As for real pain, what's in limits and off-limits? Cock & Ball torture might be an option here - think about penile restriction, ball squashing
7. Maybe this is a sensitive question - can women become abusive? With me being the dominant one, how do I ensure I don't cross the line with him? Once I hand spanked him quite hard for being late to our date whereas we usually do only roleplays. Did I mix a fantasy with a real punishmennt?
I suppose the answer here is to have an "out" - a safeword or something that he or you can use when you have crossed a line - something that stops things NOW. Beside that, talking, debriefing, communication and sharing feelings ideas and feedback.
8. He's not really into sex, more enjoys a long HJ. I also can't ask/force him to wank by himself. IOW, the only thing that works for him is HJ. Is this normal for guys? I'm happy with it as it is, just curious about this
possible death grip, where his cock is used to hand stimulation and nothing else works - the only answer is abstinance. buy him a chastity cage.
9. Is there a lube that can delay his coming? Sometimes, he comes too early for me.
You can get delay sprays, which work with missed success. what might be better, is orgasm denial, teasing and edge play. This involves you learning to read his body and stopping teh stimulation just at the right time. It can be difficult at first, but is also great fun.
I know you've said you're not into electro sex, but the one thing that works without fail for me is electric stimulation - whack the power up to full and my penis just runs and hides and will not ejaculate, regardless of how close i am.
10. Is there a male toy that's similar to a female vibrator? Would be fun to alternate between caning and turning the vibrator on. We're not into electro play though.
Lots of choice - look up fleshlights for teh best selling male toys, but my personal fave is the doxy wand and hummer attachement.
https://www.lovehoney.co.uk/brands/doxy/
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11. What is the best way to tie him up tightly while having to both his butt and penis for the vibrator toy? Sometimes he just wriggles a bit too much
Lots of options, so experiement and find what works for you.
Try this though.get him to kneel on the bed.leaning forward, tie each wrist to a leg on either of side of the bed,pull it tight, so hisarms are outstretched.then fix a spreader bar between his ankles, teh wider teh better. then fix another at knee height, slightly narrower than the first. then, strap his ankles to the other legs of the bed. He should now be in a doggyish position. Pull everything tight, make sure he is able to move as little as possible. you can straps around teh knees and waist if he is really wriggly.
There are lots of ways to acheive what you want, this is just one.