Aside from the concept of allowing two dogs to breed unchecked because your family always wants puppies, you have GOT to be seriously kidding when you say, "i just want him to stop cause he gets really emotional".
In addition to neutering your male, I would suggest your friend spay his bitch. That way, she won't go looking for a new Romeo.
"Some days you're the dog; some days you're the hydrant". author unknown