Intimacy exists in different forms. Blood bonds have a different intimacy than the other.
And nothing is wrong in this world, and since yours isn't bonded by blood as well, if you feel the same way with him, if you feel his intimacy is healthy and makes you feel comfortable, go ahead.
It is you who needs to choose who you are and no one else. Don't fear that the society might judge you. Only thing the society know is judging and nothing else. Stay happy!