What do you think?

So I’ve been on and off in love with my best guy friend for almost a year now. I give him love advice because even though it kills me, I want him to be happy even if it’s with someone else. I get jealous of every girl he tells me about, especially the ones he’s been sexual with. Tonight he told me that while he was drunk, he thought of kissing me and eating me out and I wonder if he’s thought about this before. We have a deal to get married if we are both single by 35 and he told me he’s thought of kissing me to find out if we have chemistry. He looks at me in a way where I can tell he cares for me but I never even knew he was attracted to me until just now. I told him that the next time he and I had a moment, I would go for it. Do you think I should?