Uk wht, chase knew abt Grayson's condition and he knew he lies and mimics statements. Whn Grayson lied to him abt him sleeping with a dog, chase didn't believe that at first but he was in doubt as he knew that he actually slept with someone (who was ofcourse josh). Bit no one knew abt this and Josh disappeared after removing his every trace. Chase hired so many detectives to find that person but couldn't find them. But he still was sure that he has slept with someone, that's when he started believing that he might actually have done it with a dog since such a person was nowhere in existence.
But daee I say this, ppl will come for my head.

like guys i swear grayson is not a bad b like if yall read the novel yall would know... hes just an innocncet lil puppy who doesnt know shyttt