I have a male coworker whom I have a lot of chemistry and a very close working relationship. We are best buds at my company. I was going to go meet friends for dinner and brought a cute red dress to change into. When I was showing my female coworker my dress, my friend happened to walk in. After that he wouldn't look me in the eye for a couple hours, wouldn't sit near me at lunch. Then later on I casually mentioned I was having dinner with friends and he seemed relieved and said "ohhhh okay I hope it goes well." Do you think he was jealous and thought I had a date or something?