What does it mean if a guy puts his arm around you? Is he interested?

You can just answer the first question or both (:

Aaron (A) is someone I never met. He gave me his number because I was looking to buy something and thought he would know a person who had what I needed. He wanted to hangout afterwards.

We met up and his friends were there most of the time. This is our first time hanging out.
He gave me options throughout the day to go with his friends or stay behind with him in the car and listen to music.

Throughout the day he tries to put his arm around me or right on the seat I'm using ( I couldn't lean back without leaning on his arm)
Later he asks if I'm cold and put his arm around me.
I say im good and scoot away

Well later on he puts his arm around me and I leaned on his chest
(sitting in a backseat) and his arm tightens and he rests his hand on my arm and rubbing it.
What does it mean if a guy puts his arm around you? Is he interested?
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