In the Dragon Ball Z: Super Android 13! movie, when Goku is fighting with Super Android 13, there is a scene that showed Super Android 13 punching Goku in the dragon.. uhmm... genitals.
Caution: This picture can cause unexpected pain in the crotch!
Watch it at your own risk.
Is there any evidence that Goku managed to produce Goten before that fight?
Because I have a doubt about whether he could use them ever again.
Are the two circles in the picture (that appear to be torn apart) something else?