This young woman recently found herself asking this question after she was sent an invitation to her best friend's wedding - whose boyfriend hadn't even proposed to her yet.
According to The Sun, the woman posted her ultimatum anonymously to a Facebook group, asking other people for their advice after her best friend had sent her an invitation to a "special event" which she later realised was actually her wedding.
According to the woman, her friend had played one of those Facebook fortunetelling games that supposedly predict one's future, and her fortune read that she would be getting married sometime this year.
Knowing that her friend loved the idea of being married, she went along with the fortune, telling her friend that she probably would get married some time soon.
To her friend's complete surprise she had taken the fortune to heart and began planning the actual wedding... except no engagement had even happened or been announced.
The woman's anonymous Facebook post read as follows.
"I love my friend dearly, and her boyfriend of a few years is really an awesome guy. Love hanging out with them!
"Sometime after New Year's Day, she did a Facebook game that told her she's getting married this year (those fake fortune games). I told her that I could see a wedding for them happening sometime though.
"She messaged me on Instagram today to RVP for a special event on Zola, which is when I realsied she's really been planning her wedding!"
Her friend who is obviously very confused that she received an invitation to the wedding before she was told about the engagement assumed that maybe the proposal had actually happened, but according to The Sun, during text message conversations the "bride-to-be" revealed that the engagement had indeed not happened.
Facebook users were divided on the matter with some users questioning this brides uncanny wedding behaviour while others didn't seem to think it too strange, strangely enough.
One user commented on the fact that the "groom-to-be" might not even know that he's about to get married. "Does this poor man know he is getting married? Like I could see this being one of those 'surprise baby we are getting married today situations'."
Another user however, revealed that she and her partner had started planning their wedding months before their own engagement so she didn't see how this was strange at all.
"We started planning our wedding six months before the engagement, not everyone takes the linear path," she commented.
Yet another posed two scenarios: The first being that the groom to be has no idea that the wedding is being planned or that he knows it's happening but isn't one hundred percent invested.
The other scenario according to this Facebook user, is that they've discussed planning the wedding but want to wait before making a formal proposal.
It could be either or, but still pretty strange. What do you think?