Is my boss flirting with me?

I may be over thinking things because he is my boss and married but lately he’s been too nice to me. He’s always smiling or smirking at me. Today he walked by and untied my apron and I needed an escort to walk with me because I had money and he told the guy no I will walk with her held out his arm and I put mine in his and he says we are Bonnie and Clyde. He has nicknames for me and always high fives me. I’ve never noticed him doing it to others and he said I was his favorite. He called me a lot (we both worked today) but it wasn’t anything urgent. Now am I over reacting or is he flirting with me?