What did his actions mean?

So I was over my bestfriends house and was siting in her living room and then her brother and his friends John came in and John smiled at Ron(best friends brother) and Ron gave him a digested look cause Ron thinks of me as a little sister.Then me and my friend went swimming and the boys were in the pool and John gave Ron that look again! He is so cute and I do like him so please help! What did he mean by that smile??