It's rude to keep your boyfriend a secret.
Sara is at a luncheon with some colleagues from work when a male coworker starts flirting with her.
Sara wants to entertain herself.
Sara immediately mentions that she has a boyfriend, but has fun trying to set the male coworker up with someone else.
To pass the time more quickly, Sara reciprocates the flirtatious attention that her male coworker is giving her without ever mentioning her boyfriend.
The male coworker appreciates Sara's efforts and ends up meeting a number of other women he is interested in.
The male coworker thinks that Sara is interested in him and is shocked to later find out via social media that she isn't single.