If a guy puts you on his shoulders in the pool does that mean he likes you?

Either that or he's just having fun in the pool. He probably likes you, but it doesn't necessarily mean that he likes you in any special way at all. Some guys enjoy more physical activity when they play, and given the right circumstances a guy might pick a male buddy up on his shoulders without giving it a thought. Stay friendly with the guy; maybe he is interested. But don't read too much into the guy's ways of playing around.