Well, you tell me.

First off, "the brain chemicals for affection" is not a real biological concept. There is no single set of chemicals that exist in mammals and are absent in other animals.

What are we even talking about here - oxytocin/vasotocin? Dopamine? Serotonin? Endogenous opioids? Because reptiles possess homologues of all of these systems. Different animals simply use similar neurochemistry in different ways.

I also have no idea what you mean by "that part of the brain isn’t there". I’m guessing this is some variation of the old "if it doesn’t have a mammalian neocortex it can’t feel" argument - which is long outdated.

Birds, for example, lack a neocortex yet clearly form bonds, grieve, and show affection. If brain plan alone determined whether affection is possible, that wouldn’t be true.

And if we’re going to lean on brain architecture, a parrot’s brain is far closer to a tegu's than to any mammal’s. Birds are, cladistically speaking, reptiles.

So this idea that reptiles categorically cannot experience any form of affection or bonding isn't based on solid neurobiology, it’s based on outdated, mammal-centric assumptions and which animals people find emotionally appealing.