Sorry, but boyfriends almost always trump dads. I did. When my wife was my 16 year-old girlfriend, I followed all of her dad's rules, when I was in front of him. But when I wasn't, look out!
I'm sure your daughter loves you, but she needs to learn how to be an adult. Caring for a boyfriend is part of that. Happy Father's Day!
“Caring for a boyfriend” = sex?