It seems to me that he’s interested in you. Men are so wishy washy with feelings. Most men will not tell you how they feel about you, until they know you feel the same.
I could see this being the reason that he was giving the other person in your 3 person conversation more attention than you, he was probably purposely trying to play things cool. That’s why it’s sometimes beneficial to make the first move. I would suggest subtly flirting with him the coming weeks. When he stares at you, stare back and smile.
Also, keep eye contact. This is a huge way to show that you are interested in what he has to offer and he will feel that. After a while, I would straight up ask him out. Yes, there’s a potential for him to say no. There’s also potential for him to say yes, though.
I say, take a chance and see where this will take you. You never know what the outcome could be until you try.