(NSFW) Sexual positions better for older women and men?

Pressure on her knees when kneeling gives my sweet wife too much pain to enjoy what we’re doing. She prefers to have me on top. I have less control to hold back from coming in that position.
When I’m on top for more than a few minutes, her hips start to hurt.
Fortunately, she loves for me to eat her while she is on her back as much as I adore doing so. She makes me stop after she comes hard once because she says she feel like her head will explode if I keep going. Then she wants me inside her from on top, where we can’t do it for as long as I’d like. Suggestions from any sexy, 50+ lovers?