"Dual cultivation is a valid cultivation technique. It was hardly the focus of my studies, not by a long stretch, but it wasn't excluded, either. So if you... wish, we can cultivate while we do this, too. Back and forth, you send me some spiritual energy, and I send it back to you..."

And with the confirmation that he will be allowed to know if something isn't as good as seems it will be, in his mind, Xingchen shifts again, wrapping his lips around the tip of Zichen's erection, and then slowly starts taking in more of it.

It doesn't take long to figure out where the difficulty in this is, and Xingchen raises his head up, moving up and down with his eyebrows scrunched up slightly while he considers how to relax his throat to take him in deeper. And yes, if Zichen is passing spiritual energy, Xingchen is passing it back, higher and higher. He knows it might be a lot, but - he wants Zichen to be stronger. And to feel better.