When two or more individuals meet, more commonly at a nudist beach and engage in mutual (giving and receiving) maturbation on the beach.
Today I went to the nudist beach and this guy next to me had a really nice boner, he was looking at me...I was looking at his boner and then one this led to antoher and we had a "mutual sandy handy".
When an older man puts one hand on a younger male's knee and slowly slides the hand up toward the groin region over a span of at least 5 minutes, usually making the younger male very uncomfortable. Named after the infamous former Penn State assistant Jerry Sandusky.
Did you see coach last night?
Yeah, he was definitely giving John the Sandy Hand on the bus ride home from the game last night.