Something I didn't realize until recent years when I did some reading on the subject was just HOW difficult it is to have any monkey/ape as a pet. Even a capuchin can be very dangerous. And even if raised "right" insofar as it is possible to try to make it a pet. Pet monkeys have to be raised much like human children, in the presence of a caretaker to socialize and watch over it 24/7. But even monkeys raised from infancy with experienced caregivers meeting their huge emotional needs and socializing them to humans and the domestic environment can go haywire once they reach sexual maturity, or, as has been noted here, later in adult life. They can become violently aggressive, causing injury, and other favorite things like deliberate and aimed feces throwing.
The sleeping with and bath-taking in this instance might certainly might have had a bestiality component to it (really creepy and ugh), or it might have been part of trying to keep the chimp's insatiable socialization needs met. Apparently monkeys and apes have to be in a social group pretty much 24/7 or they act out -- really, really act out.
Somewhat similar are parrots (though nowhere near as extreme), and here I do have direct experience, as a bird owner. A lot of people think a pet bird can be happy in a cage all day. Not so. Some can't even tolerate very well being alone while their owners are at work. Generally speaking, parrots should get as much attention and interaction and out of cage time as a dog or cat would, otherwise they aren't very tame and are prone to developing behavior problems like excessive screaming, feather picking, etc. Not that they are anywhere near as bad as monkeys! But still that's something not everyone realizes. Birds are not like fish or other caged pets such as hamsters or mice that can be content with only occasional interaction with their owners.
Back to chimps, my eyes were opened to their violence by the book Brazzaville Beach, a novel but with realistic depictions of chimp aggression in the wild. One group systematically and brutally attacks another group simply because the second group wanted to separate from the first group. The second group wasn't trying to invade the first's territory or anything like that, and they tried very hard to avoid the first group and move away from them, but the first stalked them constantly and picked them off by isolating one or a few members at a time and brutally and horrifically killing them in painful, agonizing ways (ripping limbs, things like that).