Zoophilia is a paraphilia in which a person experiences a sexual fixation on non-human animals.
Bestiality instead refers to cross-species sexual activity between humans and non-human animals.
Zoophilia is the act of being attracted to animals.
Bestiality is just the sexual part.
Zoosexual if I remember correctly is a term made by the zoo community to mean the same as homosexual or other sexuality names.
There is a lot of confusion around terms used in the zoo community, so here is how science defines these terms: Bestialist: There are the “bestialists” who have one or a few sexual contacts with an animal, or they use animals when a more “normal” outlet is not available. (2002, Understanding...