He's a homunculus and while he can pass at human sometimes, everything else he does is just right on the line. Again see the whole missing one translation thing
Though I can definitely see him having spent some one on one time with his original crew. Be it one of the cold-blooded types that needed a walking, talking piece of shit space heater, or simply because they snuck into his room at night
He'll creep in when he's sometimes not wanted, especially if they're obviously going through something. And hey, if he gets stabbed in the process? Ah well, it's just part of the job
He won't romance like most, he won't confess and hunker down. His eyes will always be wandering for more, but he'll come back to his usual haunts every single time as long as they want him