His age

Okay guys, I'm 16 about to be 17 (in January) and the guy I like just turned 20 (in October). My question is would you let your daughter continue to see this man or would you say no because he's an adult? You know his family very, well you know him as well, he's very respectable he has shown the upmost respect for you wishes and her safety, he works in the family business and he's asked your permission to call on your daughter.