Finally the top would need to
- force the the bottom's to stay ass up and face down (regardless of the position they used while fucking) for 15+ minutes.
- Insert a girthy butt plug and force the bottom to keep it in for a few hours with their ass up.

And a fresh infection or HVL helps a lot too ;)

Also when the top:
- has the bottom douche with higher pressure tap water instead of saline
- starts using a toy to stretch the bottom's ass right after douching,
- breeds the bottom in the first 30-60 minutes after the above.

Also, legs on shoulders is riskier for the bottom than ass up face down.

Next time you're in SF, let me know! I'd love to feel you breeding my unmedicated neg hole!