Sex itself, especially 30 + minutes with long streams of dirty talk, is cardio intensive, so that’s definitely important to keep on point. Also for blood to properly flow where it needs to.
Thrusting is largely hamstrings, so train those with high reps, like 15, with good mornings, rormanian deadlifts, and leg curls.
Your abs are also under tension often so keep them solid.
Flexibility is important for both parties. For the woman especially at the hips. Perform both active and passive stretching. Magnificent mobility is an excellent resource for the former. A standard textbook set of stretches, or ideally even basic yoga, for the latter.
Forearm strength is important for holding her down, tightening knots, etc.
Next, having a good mind muscle connection in terms of isolation body control is helpful for both what you can do and your level of enjoyment.
One way to achieve this is with dance.
In popping there is a movement called the wave. Learning to do a wave through your arms, down your chest, hips, and legs and back up is really powerful in helping you learn to guide your body in aesthetic ways.
In bachata there are also waves, wherein the man guides her movement with his body to produce a sensual waving of her body. As a bonus, with partner dance, you get to experience extended but a subdued sexual tension, and for tantric development having a taste and appreciation for a diverse range of sexual energy levels is paramount.