Your ex starts dating
That's when the definition of "breakup" is no longer unclear.
If you weren't broken up before, you sure as hell are now.
Eventually, you start talking to your ex more frequently.
You might start drunk texting each other and flirting, which might lead to meeting up late at night and having the infamous, you-swore-you'd-never-do-it breakup sex.
Or maybe you didn't even realize you were holding on to the fantasy until the moment your ex actually got with someone new. You know how deeply connected you once were with your ex, so knowing your ex is feeling that deep of a connection with someone else confirms the fact that you are no longer relevant.
Maybe you moved on, but an unexpected wave of nausea still washed over you when you saw your ex tagged in a photo with that new person on Facebook, which made you feel betrayed. At one point in your relationship, you and your ex were convinced there was nobody else either of you wanted to be with. Your ex was your everything, your partner in crime, your number one person.
"Even though you might "officially" end a relationship, you probably don't cut your ex off right away.
You probably still follow him or her on Facebook, Twitter, Instagram and Snapchat, so you still feel like you're a big part of his or her life.
You wave from afar, minimize giggling and refrain from having casual texting conversations.
Now how you know a relationship is really, truly over.
Whenever you ask newly single friends when they and their exes broke up, it's normal to hear them chuckle and say "officially or unofficially?
You maintain levels of platonic friendship that you guys had never done before.
These newfound boundaries prove that not only is the relationship really over, but the post-breakup attention you were used to is really over, too.
During your post-breakup period, it was easy to push your limits with your ex, whether it was with those drunken hookups, calling him or her late at night "just to talk," laughing together at parties or joking about the silly or embarrassing things that happened in your relationship.