Like both of them looking back: neither of them want this to end, whatever "this" is or might become. Then, after the tattoo is removed, Satomi said he wants to start on equal terms: starting a relationship as an equal adult, not as a kid, and also not as a teacher. Kyuoji said goodbye with a pat and not a proper hug because he said goodbye for the night, not for good.
BUT the author left a the door open.
Like both of them looking back: neither of them want this to end, whatever "this" is or might become.
Then, after the tattoo is removed, Satomi said he wants to start on equal terms: starting a relationship as an equal adult, not as a kid, and also not as a teacher.
Kyuoji said goodbye with a pat and not a proper hug because he said goodbye for the night, not for good.
At least in my starry-eyed interpretation. (: