How to find out if my best guy friend likes me?

So, I am totally confused. I have this guy that has been one of my best friends for a long time. We have known eachother since I was in 5th grade. I am now almost 18 and he is almost 17. We dated once when I was a freshman in high school but in the end, we decided just to be friends. Lately, our flirting has reached new levels. He holds me for long periods of time. He tells me he he misses me and not to leave. He encourages me to be single. He flirts with me like there is no tomorrow! He pokes me, tickles me, puts his arm around me, holds me, picks me up, and has even held my hand. I never thought I would ever see him as more than a friend but lately, I have started falling for him. He is so sweet and open and honest with me about everything. He truly cares and is there for me when I want to cry. I have just gotten so hurt by past relationships (even one where we talked marriage) and I am so scared to tell my best guy friend how I feel. If he doesn’t feel the same, our friendship would change and nothing would be the same. I also kinda feel like I have made it seem like I don’t want to be in a relationship with him, tho, because when he asked me about more than flirting I said yes and no and told him that I didn’t want to lose his friendship or get hurt and that he was too much of a flirt. Obviously, everybody is telling me he likes me and he’s showed signs left and right with both words and actions. Still, being his best friend, I also know that he (in the past and still some recently) is a huge flirt!!! However, he is being open and serious as well as flirty with me. We have talked about a relationship again (its been 3 and a half years) and he has even jokingly asked me if I loved him. ALL THE SIGNS ARE THERE so why do I feel like he is just playing me? I don’t think he is but its hard to tell because he is a flirt. I have known him for almost 8 years and I have done the unthinkable..fallen for my best friend. Do you think he likes me back? Should I tell him? What should I do? HELP!