We often forget how nasty, vicious, and unpredictable real fights actually are. They’re not like what you see in movies or in fantasies. Once things get physical, you can’t always control what happens next. The chance of something going seriously wrong is really high. All it takes is one bad move and someone hits their head, breaks something, or worse. That’s why in a situation like that, I’d always want my boyfriend to stop the fight. It’s just not worth the risk.
On the one hand, I agree with you about the risk of serious injury in a fight, and I'm afraid of that too. But on the other hand, I'm afraid of looking like a weak bitch in my boyfriend's eyes if I ask him to stop the fight.