Single….ish

I recently became a single gal! But I’m interested in a more mature guy. The problem is he’s already spoken for. There are feelings there on both sides. Should I just move on and let him go? I’ve been asked out by other guys, but I turned them down….. was that wrong? Should I just except that I need to start seeing other men… I’m just so confused he makes me laugh and I get excited every single time I see him. He’s quirky (which I adore) he’s flirty and fun, he makes me feel me again! Should I stay away? Should I see where things go?