Ever been in love with your best friend?

I cant hide it any longer. I am in love with my best friend of 6 years. 
And i dont know what to do. What do you do? Do you tell them and risk ruining such an amazing friendship or keep this secret in forever and watch them love someone else? 
He called me his baby and said he loved me the other day and i about lost it. I probably sound so stupid right now. I just dont know what to do and what not to do. 
UPDATE: we talked about it. And decided we wanted to give it a shot. A week later, he was in a relationship. They broke up after 5 days. We talked as friends then he asked me to be his girl but i told him i'd like him to treat me like a princess and take me out. He agreed. 2 weeks later (today) he's talking to another girl. Call me miss moving on! I deserve better😴