Is it normal that he isn't talking to me?

So this family friend and I have gotten close. We've known each other for three years and really get along. His siblings and I don't really talk and every time I'm at their place it's always me and him hanging out. He laughs at all my jokes and vice versa, and I've had some deep talks with him. He makes sure I'm okay when it looks like I'm not, takes me everywhere with him, and we always have a cheesy long eye contact moment. His sister unfortunately found out that i have feelings for him, and suddenly shouted it while we were all eating dinner. I simplu played it off and laughed. All he said was, "Okay." Now, i may be overthinking this. But it just seemed so much like he was interested in me. He doesn't act like that to my sister. I'm the only one he talks to. I'm so comfortable around him. We shared a hammock. We've both kind of distanced ourselves. We aren't as close. I haven't seen him in a while. Is this normal? How am i supposed to know what he feels?