Does anyone know if there's a method to slightly damage a man's urethra in a way that makes ejaculation extremely painful until it heals, but doesn't cause actual permanent damage?

Also, I've read that in order to rupture the average testicle through squeezing, about 50kg / 110 pounds of force is needed. Anyone know what the average threshold for causing permanent damage is, assuming medical help is unavailable? Or are they fine as long as a rupture doesn't occur? I know the durability of the testicles can vary widely between individuals, so for context, the victim in question is young and healthy, but would most likely not have much (if any) past experience with groin trauma.