That was debunked.
National Geographic:
No, Those Aren't Male Lions Mating. One Is Likely a Female.
The only ape that is gay/bi is the famous bonobo. Which proves that bi people are sex mad fiends - incapable of forming monogamous relationships, unfaithful and their habits led to the spread of STDs like AIDs, syphillis.
https://terriblyterrier.com/can-dogs-be-gay/
So yeah, if your gf says she's bi. That's great - for the college period. Use her to get threesomes for yourself. But then dump her when you leave college and want to start a family, because she's wired to be a bad wife and cheat on you.The bonobo appears to be bisexual as a species. These great apes, which along with the chimp are the closest relatives to humans, will use any excuse to have sex or masturbate. Female-on-female sex is particularly common.