Male friends fiancé gave me a bad look when I touched his arm?

I was out with a group of people, including my male coworker friend and his fiancée. At one point I gently touched his arm during conversation, it was quick and more like a tap. I saw her give me a bad and jealous look and I felt uncomfortable. Was I out of order, surely touching an arm isn’t that bad?

Male friends fiancé gave me a bad look when I touched his arm?
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