I have no interest in marriage. I got unmarried just a few months ago. Like many others in this thread, I like living alone and the tax and other government benefits given by the marriage certificate simply aren't worth the risk. No need for government blessing of my relationships.
I am not sure about romance. I wouldn't call myself a romantic guy. But I might be motivated to do some romantic gestures at times. I would not mind having a life long relationship with a woman who feels similar to me about having your own place, marriage, children, monogamy, etc.
The sex drive still runs strong. I love it.