The genitals of dogs are very special. They will have barbs after successful intercourse. They cannot be forcibly pulled out until the genitals become smaller. If they are forcibly pulled out, the dog will scream in pain. The reason why dogs evolved in this way is to increase the success rate of pregnancy, so we should not make a fuss when seeing this kind of situation.

Tip:

When mating dogs, you should choose dogs of the same breed with similar body shapes to avoid some unexpected situations.