as a unit *before* spending one on one time with the little guy and now he loves him by himself (which is not to say he loves the other big guy any less)
I think Jin liked what the other two had together. He wanted to be a part of it. But then he got to know them better as individuals too and actually fell for both of them as individuals.
Wait so dies he like him as an individual or was he telling the truth and likes them as a unit?