What does it mean when a man kind of opens his mouth and slightly sticks his tongue out when you’re speaking to him?

He was flirtatious, showed off his body, was fishing for compliments as to how handsome he is (he doesn’t want a relationship) but still mid conversation he opened his mouth and his tongue was slightly sticking out and I felt like he was maybe being suggestive or something (we have kissed in the past but that’s about it)..
What does it mean when a man kind of opens his mouth and slightly sticks his tongue out when you’re speaking to him?
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