Always liked it
First time getting wet clothes was at my first swimming exam when i was six, i cannot remember much about it but i remember that it felt quite funny to swim around in your clothes.
I didn't know that i really liked it at that time but years later i had this strange urge to play that i fell into the water and swam around, and it only took a couple more years before i really did so.
I am unfortunately not swimming in clothes that often, it's hard to find occasions, most of the time they come when being thrown into the water. But that makes those few times really special, and really enjoyable.