My wife and I are in our 50's (we're middle-aged, not ancient), I'm a little round in the belly and she's a little round in the bottom. She'd like to start trying Tantric sex and the first steps seem to involve getting into the Yab Yum position with her on my lap. She's a little worried that we can even do this. I'd like to be able to calm her nerves a little and simply suggest a modification if needed. Maybe I'm just searching on the wrong terms, but Google is giving me a big, fat (no pun intended) zero on modifications for this pose, but surely there must be something?

Can anyone please offer any suggestions on how to modify the pose for total noobs on their first venture into this pose, for people with a rounder physique?

Thanks!