He wants to add sex to our friendship...?

My best friend is a guy who I work with. We get along SO well. I’ve had a crush on him for the last four years....and he knows it. He has had some issues with addiction in the past and says he’s afraid to date me because he doesn’t want to ruin my life and that he’s not good enough for me. I’ve tried to date other guys but it never works out. Recently he told me that instead of me messing around with other guys he and I should just start having sex because I know him well and he’d be a safe option to have sexual relations with instead of strangers. Do you think he will ever want to date me? Or will we only ever be friends with benefits (if I decide to become sexually involved with him) ?