This is actually a lot safer than it looks!
Rays have crushing plates in their mouths, but no significant gripping power, so they can’t grab a hand and pull it. You have to sit still and let them get your fingers into their mouth for them to actually put the plates to work. Also, the sharp bits are on the other end, and they only sting when threatened. Clearly, this ray does not feel threatened.
Rays also tame pretty easily when offered food, as seen above.
BettSplendens Tumblr Evac 