The December issue had an interesting section on falling in love. My favorite article was actually « The Happy Couple » which explains how to stay in love.

In short focus on the positive. There is no worse destroyer of love than saying « That’s nice honey » to your partner’s excitement over something positive that happened to him or her.

The article is not available for free, but you can get a preview at:
http://www.scientificamerican.com/article.cfm?id=the-happy-couple