The Taoist practice of withholding physical ejaculation is reported to induce multiple non-ejaculatory orgasms. After much practice, years ago, I had it happen. Once.
The idea is that the male penis is basically a sponge, and by not ejaculating, one not only retains their own potency, but also through the sponge, absorbs balancing female energy.
Cunnilingus achieves the same female absorbtion, but with a reduced level of excited/recirculated Male Qi.
Class dismissed.