Is it right to evolve a friendship with the opposite sex into a "close" one when married? To the point of chatting with him/her first thing when you wake you up in the morning and the last thing you do at night when you don't even do it with your spouse? I call that cheating. What do you think?

Sounds like a disaster waiting to happen. I would not like it if my husband message a female first thing in the morning and last at night. As for me I have lots of male friends but the one I married is my best friend and I don't do that even when some of them I have been best friends for years...