And Lyon says...

Lyon comes in and tells me something that I can't understand, but somehow 

I get the message that he needs his swim shoes. 

 He finally says clear enough for me to understand:

"-K- said I need to put on flip-flops 

and I don't even know what flip flops are!" 

I could not stop laughing as I tried to explain to him what flip flops are. 

 I show him his sandals and explain how they go, flip-flop-flip-flop when he walks. 

And that is why they are sometimes called "flip flops".

 Of course I could not stop laughing as I had this conversation with him

 so I'm not really sure how much he understood... 

...I don't think he got it, because he keeps calling his swim shoes "flip-flops" and his sandals "sandals"...

 Lol!