I think I've read too many stories of dads trying to discipline their daughters' boyfriends and it ending up in tragedy.
Ultimately, you're only really responsible for your daughter, I don't have kids, but I'd like to think I'd be able to establish a relationship with a potential daughter wherein she understands the risks in having boyfriends at a young age, and I wouldn't be allowing them to come/stay over. You need to stress safety and consequences to your kids.
Putting hands on other people's kids - or just putting hands on people in general - can often come with consequences that cannot be walked back