my Mum was given to saying No in a tone of voice which really said 'Who's Mummy's darling then?'
Nobby and Seniorboy are the same, as are our mums, it seems. I really disliked Nobby when she had him because he was a nasty little biter and used to bully his brother who was bigger but more submissive. His brother died a few years ago and I felt so sorry for him not being the favourite. But that's anthropromorphising. I'm sure they got on in their catty ways.
Nobby would do that thing where he'd insist on sitting on your lap then when you weren't expecting it, suddenly grab your hand in his teeth and disembowel your forearm with his back claws. You could never sit down or stand near a flat surface because Nobby was always swaying to leap on you, claws outstretched.
Nobby would groom his brother a lot, which my mum thought was sweet, but I thought was him asserting his authority over his brother. He'd use it to physically push his brother away if he grabbed the nice spot on my mum's lap first. Nobby would lick and lick and push and push until his brother wandered off and then he'd take over the spot.
My mum thought this was all so adorable. Perhaps, it was, if you lived with him all the time and saw his well hidden good side.
When she died I adopted him because no one else would put up with him. He was a really unlovable little bastard. Clean, but that's about the most you could say in his defence.
For about two months I absolutely hated him. I wasn't cruel. I'd feed him, water him, clean his litter tray, stroke him sometimes but otherwise avoided him and would push him off my lap.
Then it changed. I think you're right and I might have stumbled inadvertently onto Exclusion From The Presence that you say Siamese cats have.
He is an absolute joy. Everyone says it now. I cannot remember the last time he bit or scratched. He loves strangers, even when one jabbed him in the scruff of the neck yesterday.