@alejandrop,
This is a lot to do with having testicules of the wrong size and temperature, with coldness helping make the area bland instead of excitement.
One way of making a cure is to massage both testicules with iciness without yelping. Don't worry, no, as smiling with the teeth will happen later when you warm them up again and excitement returns.
Bearing in mind the temperature of your partner's receptacle, make the advances and settle in properly before promoting vigour. This gives you a chance in receiving calm thoughts into the cranium and preventing too much urging to the dangerous zone.
Make sure your partner's receptacle is in full gratitude before commencing with your advancement of the active section, all the while keeping your testicules distracted with thoughts of another matter.
When your partner indicates that he or she wants to stop and make beverages, it is then customary to bring all thoughts into line with your urgings, and hasten your physique considerably until sudden purging is experienced.
Always have cuddles post purging, as it strengthens your partner's bearing towards you and achieves regard.
Good luck.