Am I overthinking?

So I have a friend at work that I hang around. We make jokes, play around but he is married. He picks on me a lot, has even given me a nickname and teases me around others. Lately, he's started acting oddly like refusing to talk about his personal life. We work with his wife, and yes I know this is odd but he won't say I love you to her or be affectionate if he knows I'm around just passing through. He acts guilty if he gets too friendly with another female around me. Am I over thinking?

Am I overthinking?
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