I feel like raph out of all his brothers is the biggest hugger. I can't explain it, but I definitely seeing him constantly hugging you, platonic or not.
He's a big physical affection guy, so ruffling your hair or even resting a hand in your shoulder is common.
When cuddling raph by default is the big spoon. He yearns to be small spoon, to have that kind of safe security he gives other people, but because of his spiked shell he would rather just enjoy cuddling you and not worry about hurting you.
I see him preferring to have you on his chest while he slept on his back, or spooning you and using you as a stuffed animal.
When you offered for him to lay his head on your stomach he didn't think he'd like it as much as he did.
He loves to give you smooches periodically throughout cuddling, like the big kind where it makes a noise. He likes your reactions to it and generally he likes being about to be vulnerable with you and exaggerate gestures of affection.
He almost always enganges in the cuddling, so when you ask for some he ends up half tackling you and running to his room.
He's surprisingly vulnerable with you, so if you were to roll over and stop cuddling him raph would get sad- even if it were only in your sleep. You would have to apologize to him in the morning and assure him that you were not mad and it was an accident.
In conclusion, raph is good boy.