Facebook data scientist Carlos Diuk breaks down what happens in the days leading up to (and immediately following) two Facebook users beginning a relationship.

Here's what Facebook sees when you fall in love.

Up until the day you two make it official (the "0" in the x axis), Facebook notices an uptick in the number of timeline posts you and your soon-to-be significant other make on each other's walls. This is the metric that gives it all away, apparently.

Diuk writes, "We observe a peak of 1.67 posts per day 12 days before the relationship begins, and a lowest point of 1.53 posts per day 85 days into the relationship. Presumably, couples decide to spend more time together, courtship is off, and online interactions give way to more interactions in the physical world."

Even though there are fewer messages being sent between star-crossed lovers the longer they're in a relationship, Diuk says " the content of the interactions gets sweeter and more positive." By using "statistical methods to automatically analyze a set of aggregated, anonymized timeline interactions[...] we counted the proportion of words expressing positive emotions (like 'love', 'nice', 'happy', etc.) minus the proportion of words expressing negative ones (like 'hate', 'hurt', 'bad', etc.)."

Diuk's conclusion: before a relationship officially kicks off, the two soon-to-be participants are communicating often via Facebook. They later use the site to say fewer things to each other, but those things tend to be more positive.