My boyfriend has really bad teeth How do I get him to take better care of his teeth?

I've been dating this guy for 5 months and his teeth and gums are starting to really get to me. Near his gum line it is black and his gums bleed a lot. They even bleed sometimes when we kiss. Gross! We've talked about it a little. He says he never flosses and hasn't gotten a cleaning in a long time. His parents even gotten him an electric tooth brush which helps a little. I commented how good it worked when he first got it but he doesn't like to use it b/c it makes his gums bleed. I mean he's 21 years old, he needs to learn how to have better dental hygine. What do i do?
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You need to tell him straight up yo. Nasty teeth ain't no stuff to mess with bia.
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