I really want to try him riding my strap on but not sure on best positions anybody done this before?
I am still new to pegging and we have only tried doggy so far. We both want to try pegging a bit more and with experience will come positions I guess. I should imagine him on top is quite easy?
Yeap, being on top feels just as good as doggy, if not better. My first time on top, I felt a bit self conscious, but in terms of being able to control angle and depth it's great. Much easier to achieve a prostate orgasm too!
Take my word for it as I have done it to a few guys, doggy is the most comfortable so start with this and then move to missionary
We have tried doggy and missionary im to short for doggy and can't reach we like missionary and I love the access to his penis to make him cum but we would like to try other positions too though.
Mrs Rimmer here, the way I like to take Mr Rimmer is to get him laying on his back with a couple of pillows under his arse, with both arms stretched out behind his head and tied with ropes to the legs of the bed, and then getting his legs over my shoulders....for an old guy he is quite flexible 
My other one is to have him bent over the bed or couch, again arms tied above his hea to the legs of the bed or couch, but wit a extendable spreader bar at its max width and ankle restraints keeping his legs apart, showing his tight butt, and ready for the taking with a 12inch long x 7inch girth real life dildo......OH!!! what fun and one happy Lady 
I always knew Mr Rimmer was a lucky guy!
I like laying on my front as she enters me from behind but as long as she's in me I'm happy 😁😁😁
Similar to the 'Side Slide', him on his side with both legs curled up so can be penetrated from behind with her kneeling and thrusting
Only done doggy so far, but if I'm watching bi/shemale porn then cowgirl or reverse is my favourite to watch. Love seeing the big dicks bouncing up and down!!
Sitting astride my OH with her strap on and harness on can lead to penetration being a little too deep into vital organs. I realised this when a kidney popped out of my ear.
I think Mr Rimmer is one lucky gut