Wet love

So, every Tuesday and Wednesday I take my disabled client to the local swimming pool and I always see this guy there. We always say hello and introduced ourselves to each other. Today I went like any other Wednesday and as I was saying goodbye, he waved and winked at me. Could someone please tell me what this means! Is he interested? Or is he just being friendly? Help! I searched him on fb and he had a gf last time i checked. But I’m really interested in him. Please leave any advice or opinions xx