Are these mixed signals or the sign of a potential cheater?

So a guy friend of mine has started dating a girl in the past month. In spite of that he is always teasing me, he stares at me when I’m not looking, he watches me when I’m talking to other men, he has made suggestive comments at times, he is playful in some ways, and even last weekend he took my hand, looked in my eyes and started stroking it tenderly and in proximity to the girlfriend (although I am quite sure she did not see.) Why does he do these things in your view?
Are these mixed signals or the sign of a potential cheater?
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