love help

i love a guy who is married , he is understang , sweet , caring , loving , everything , its not that i intend to break his marriage but he is not happy with his wife , we used to have lovely chats on all days but now the thing is he wants to behve a bit formal , its not for his sake that he is saying such words but he cares about the world .... " what wil the world think" . He loves being and talking to me but he is now worried abut all this crap.... pls help me i want him to behve the way he used to be .. .i tried talking about this to him but he doesnt seem to understand ... pls help