Evolution from acquaintance to friend . . . to more ?

I think it is possible to go from friends to lovers. I think the two of you need to go on a date. I think it's always good if the man does the asking, but he may be waiting for a signal from you. If you have always had a business relationship in the past, he may be reluctant to jeopardize that. Have you been flirtatious? I'm not talking in a sexually suggestive way, just the usual stuff. If you all have so much in common, perhaps you could suggest a low-key outing involving one of your interests (this would qualify as a date).