My mistress and I were having an amazing obedience session a few days ago. She messaged me and instructed me to tie myself to the bed, ass up, so she could administer punishment for being disobedient. I've gotten pretty good at self bondage which makes it fun because I can really get myself tied up to where it's impossible for me to get out alone. It does take away some of the power exchange and control if she were to do it to me, but I don't think she really gets in to wanting to do all of that, she just wants the end result lol. It turned out absolutely amazing, she started and didn't stop for over an hour and a half. I was actually on the verge of tears she was hitting me so hard and she refused to stop. The only thing that could have made it better would have been if she put on our strap on and just plowed me until she came or I couldn't take it anymore. She's super apprehensive to try using the strap-on on me, or allow me to use it on her. I'm not sure how to convince her to give it a shot either way. It could be a lot of fun!
Re: strap on: getting a realistic one (dual density), only a little bigger than you, and warming it up really helps get her used to it. Start by hand with lube and ask her to guide you. Once she likes that proceed to strapping it on next time, etc. Too many ruin it with oversize or plasticy dildos and turn their partner off. Once she likes receiving it this way you may have an easier time suggesting pegging (get a different dildo for this of course).
I like Vixskin dual density. Mustang or Ranger are good sizes. We got the Ranger in VixskinX, but I dont think the X (triple density) is worth double +.