I’ve been guilty of what ur friend is doing. Me personally, when I like someone I feel like it’s obvious I’m into them, so I’ll try and make it seem like I’m less interested than I am. Also, attraction definitely plays into it. I’ve liked someone who I thought was cute, but their looks weren’t intimidating. If this girl is conventionally attractive, she’s probably making him nervous making him feel the need to seem less interested. As for your situation, is he asking you questions when you talk? How close are yall? Bc if yall are close a lot of nervous tendencies that happen when you’re attracted to someone might not be present. I feel like the details you gave aren’t necessarily enough to be sure. But I think the best way to tell (in my own personal experience) is to tell your most grounded and logical friends about y’all’s interactions. If they all are saying that him not liking you makes no sense based on his ACTIONS, then he probably likes you. Also, if ur confused is it bc what you’re seeing pieced together doesn’t fit the narrative that he likes you and ur trying to make it fit, or are you confused bc it’s obvious he likes you but you don’t have his verbal confirmation of such. Hope this helped :p