Great video!! I love to tuck my little testicles up inside. Sometimes I use a bit of tape or a rubber band to keep them up. Love the feeling of waking with nothing between my legs
As the testicular cavities are within the body cavity, some [many?] martial artists do this with their balls when preparing for a fight. It provides for greater protection than a martial arts cup alone would. It should be noted that those cups are banana shaped and offer protection for the penis but none for the testicles. However, the sides of the cup do press against the openings of the testicular cavities assisting in retaining the balls within the cavities. So, there's that. In order to make it easier to press them into the cavities, one should first assume a stance as though riding a horse. This is referred to as the "riding the horse" posture by martial artists. [Note the use of the definite article 'the' as opposed to the indefinite article 'a.'] I suspect this is because many an ancient horse rider did this to protect his eggs from being pounded while in the saddle ... LOL! Experienced, long-term partitioners are able to retain their balls for extended periods of time but novices should restrict their time in the "saddle" to a few hours at most. Reminder: Sperm is heat-sensitive which is why the balls are suspended outside the body-cavity. But gay men have little concern for that ... LOL!