Love vs. Happiness

Can you be in love and not be happy? A friend and I were talking. We were going over our current relationships. During the convo, my friend asked me how I know that she is the one. I proceeded to tell her how beautiful
things were and how I have seen how this relationship has brought me nothing
but good things.

I turned things around and asked her the same thing. I thought her answer would be like mine, instead of telling me about the good things in her relationship. She tells me what there current situation is. I
asked her, are you happy. She never answered, yes or no. She kept on going back
to there current situation. The only thing she would admit to is loving her
man.

So I ask once again, can you be in love with someone and not be happy?