Why is my cat like this?

When I first got my cat he was seperated from his mom to early so he clinged on to me and always meowed for attention, now he's big and ignores me and likes to outside but at night sometimes he cries for me to let him in, my grandma don't like cause she says he's not a very loveable cat but to me when he wants to be he snuggles and pures and loves to act like he's breasting feading off my blanket when I'm in it like I'm his mommie? And sleeps on my neck too, he does let others touch him but he's not loveable like that with them at he's kind of stuck up lol why is he act like this weirdo??