Former lovers meet again

• Character A is on their way to sell the engagement ring they once bought for Character B (but they never got to propose) when they run into Character B again.
• Character A moved out of town after the breakup. Now they need to come back for a few days and all hotels are booked full and the only person they can turn to there is Character B.
• Character A is injured. Character B works in the ER.
• Character A is injured. Character B is still listed as their emergency contact.
• Character A’s family doesn’t know about the breakup and they keep insisting Character B comes visit. 
• Character A misses a dish Character B’s mother used to make so they call for a recipe.
• The characters have a child together and are both invited to school by the kid’s teacher.
• The characters are actors and are cast in the same project. Bonus points if their relationship was a secret.
• The characters are both invited to a mutual friend’s wedding. Bonus points if they didn’t know they shared this friend.
• Character A stumbles upon Character B’s dating profile.
• The characters do the same sport and meet again at a competition.
• A friend tries to set the characters up, not knowing they used to date. 
• The characters are hired by the same company and meet every day in the office.
• The characters are suspected of a crime which happened while they were dating.
• The characters meet again only without realizing whom they are talking to.