Is monogamy natural?

Tweet

So, I just read an article on an interview that Scarlett Johansson did with Playboy. In the piece, she says basically that monogamy is work and because it is work, it is not natural. I don't dislike ScarJo but that statement is kind of nonsense. Why take vows in marriage if you aren't going to be true and faithful to only your significant other or spouse? I've been married going on 5 years this April and not once has it been difficult to remain true to my husband, physically and emotionally. Yes, when he's snoring like a bear at night, I wonder (multiple times) why I agreed to marry him but the snoring doesn't make me want to go find a quieter model. Marriage and monogamy come pretty naturally and easily to us. I think monogamy is a conscious choice. Either you want to be committed to one person or not. That easy. What are your thoughts on the naturalness of monogamy?