IF you choose to breed your male, DO NOT punish your dog for “doing what comes naturally”. It is you who set him up for mating behavior for the rest of his life. Neutering often does NOT change established behavior patterns.
Your friend’s female comes for a “love fest”. Females are receptive to males for a short time. If the female is presented early or late, she becomes a force to be reckoned with. She snaps, twists, grabs at ears or worse, growls, mashes the male to the ground, and “takes his head off”. Young “stupid” males simply go back for more. He’ll forever spin his wheels and may become nasty about his personal hygiene. “Turned on” males smell like a Billy goat! Be aware, Doggy Panties on females does not detract from their charm and may not prevent a mating you don’t plan on.