Chances are you'll start creeping your ex-partner on Facebook, new Western University research shows.
Then you'll move on to creeping his new partner - or who you suspect is his new partner.
You'll probably also re-read and analyze your previous Facebook messages and wall posts and maybe delete pictures of the two of you together in happier times.
"I wanted to see how break-up distress is related to Facebook use," said Veronika Lukacs, who next week will defend her Masters thesis, called, It's Complicated: Romantic breakups and their aftermath on Facebook.
"What I found was that whether you were on Facebook all the time or not, your distress level changed based on how much surveillance you were doing (post break-up)."
Lukacs' research surveyed people who'd broken up with an boyfriend or girlfriend in the past 12 months.
Subjects filled out a survey about their breakup experiences. Lukacs also conducted interviews about the subject.
Her hypothesis that Facebook increased post-breakup distress proved true, often because of so-called "creeping" - checking out an ex-partners profile to check up on what they were doing.
Lukacs found that 88% of respondents creeped their ex's page, and 80% looked up their ex's new partner or suspected new partner.
"The more surveillance there was, the more distress there was, but it's difficult to say why," Lukacs said.
"Does surveillance make you more distressed, or are you distressed so you do more surveillance? My hunch is that it's a bit of both."
Facebook has added a tricky dimension to a breakup, one where people have to change their relationship status and encounter an ex's smiling face in pictures posted on a mutual friend's wall.
And a solution isn't as simple as deleting an ex from your friend list, Lukacs' research found.
"Deleting seemed to be really effective for some people, but it's severe and it comes with a lot of social layers," she said.
Deleting a friend on Facebook is seen as rude and may strain relationships with mutual friends.
"Deleting seemed to be really effective but it depends on the severity of your creeping behaviour. Some people are active Facebook creepers and seek out information while others are affected by what comes up on their news feed," Lukacs said.
Once piece of advice rang true throughout her study: People should change their Facebook password post-break-up. Several survey subjects admitted to hacking into their ex's profiles, or being hacked themselves.
48% of people remained friends with their exs on Facebook
88% creeped their exs
70% used a mutual friend's profile or logged in as a mutual friend to creep their ex
74% tried to creep an ex's new partner or suspected new partner
64% said they re-read or analyzed old messages from their ex
50% deleted pictures of their ex from their profile
31% posted pictures to try to make their ex jealous
33% posted a song lyric or quote about their ex as their status
52% said they were jealous of a picture their ex posted