Luke just got home from the vet a few hours ago and seems to be doing great. He was neutered this morning. He is walking around and I'm giving him space. The vet used a laser vs. a blade and apparently this is a less invasive procedure and the heal time is lessened because there are no stiches. Luke was laying on the bed, resting and I was in petting him and my other cat, Charlie came in and was sniffing him and investigating after he'd been gone all day... and the weirdest thing happened.

He sniffed his neck and back area and got down to his butt (were Luke was snipped) and he totally freaked out. The hairs on his neck stood up, he started hissing, and growling. He never really does this unless he meets a new animal or a person is messing with him. I'm wondering why he'd do this? Could Luke smell differently from being at the vet today? Is Charlie tripping because his balls are gone? Luke is the one who had the surgery and is doing fine, but Charlie the drama king is freaking out, per usual. Anyone have any insight?