I just removed my ureteral stent yesterday morning, is it safe to masturbate or should I hold off? I'm no longer having stinging when I urinate.

Ok but... It is okay to masturbate as long as being aware that the bladder & urethra may still have some residual lingering effects of procedure-related lining inflammation which may induce mild discomfort during masturbation and at orgasm. Of course, the degree of possible discomfort may widely vary among individuals. On life reality? To articles in http://formefirst.com/onLifeBasics.html. All the best....
Ureteral stent. A "ureteral stent" is usually part of treatment for "kidney stones". The ureters are drainage tubes for the kidneys, and have nothing to do with the storage of semen in the vas deferens. Check with your urologist, but there should be no contraindication to masturbation at this point.