And yes, adult otters do hold hands when they're sleeping so they don't drift away from each other.
But otters are also brutal rapists, and one was even observed raping a baby seal, to death:
A weaned harbor seal pup was resting onshore when an untagged male sea otter approached it, grasped it with its teeth and forepaws, bit it on the nose, and flipped it over. The harbor seal moved toward the water with the sea otter following closely. Once in the water, the sea otter gripped the harbor seal’s head with its forepaws and repeatedly bit it on the nose, causing a deep laceration. The sea otter and pup rolled violently in the water for approximately 15 min, while the pup struggled to free itself from the sea otter’s grasp.
Finally, the sea otter positioned itself dorsal to the pup’s smaller body while grasping it by the head and holding it underwater in a position typical of mating sea otters. As the sea otter thrust his pelvis, his penis was extruded and intromission was observed.
At 105 min into the encounter, the sea otter released the pup, now dead, and began grooming.
The rest of this shocking Dark Side Of Otters Story Is Here