<human>: I have been getting to know a guy for a few months. I am getting out of a relationship so I didn't start dating him until recently though he has been pursuing me quite hard. 

Last night he invited me to an event and from what I picked up- while there he met a friend of his friend who is a spin instructor. The instructor invited him to her class. 

When I got there he started paying attention to me exclusively but also went over to chat with her at one point in the night. Then as she was leaving and walking by us he stopped her to say "are you leaving?" They chatted a bit more and she asked for his card. 

I was sitting next to him the whole time this happened. We are not exclusive. But this made me feel a little strange.

Should I talk to him about it or leave it? Is this a warning sign?

Give me a shortened version of the text
<bot>: If you were hanging out with someone you were dating and they gave their card out to a girl would you say something?