Ego plays a massive role in a guy's personality and so does the presence of a supportive partner. Just like you love to lean on his shoulder, make sure that yours is available when he needs one. Be supportive of the things he does and the things he believes in. Give him compliments and give his ego a slight boost whenever he is down. Slowly but surely, he will be addicted to the kick he gets every time he is with you. And as a bonus, this feeling will make him miss you every time he is away from you.
It's like with dogs or children — you stick to your guns and you politely, patiently repeat the boundaries until they respect them. He gets it or he gets lost. Period. If you truly start to follow this theory, he'll feel how serious you are about being respected, and if he's at all serious about you, he'll get aboard the good boy train very fast. He'll know that if he doesn't, he'll be left at the station!