Nobody ever wants to be cheated on, but what happens when you catch someone cheating on a close friend of yours?
While it is tempting to just confront the cheater and take him or her down "Cheaters" style, you're better off collecting evidence for your friend says dating coach Chantal Heide.
"Everyone deserves to know the truth about their relationship, and it’s only through the truth that one can make an educated decision," she tells the Huffington Post Canada.
And while Heide says you should never confront the cheater during the act, you could always hear their side of the story later.
"Cheaters will want to justify their behaviour, so acknowledge what’s true while letting them know they still hold responsibility for their actions," she says.
But what if it's just an acquaintance? Should you still let them know about their cheating partner? Heide says it depends.
"If it’s a friend then I know I can help them work through whatever the issue is, but when it comes to acquaintances I need to consider what could happen after something like that is disclosed," she says. "There are always ripple effects to this kind of situation, and it all needs to be considered."
Watch the full video above to find out when Heide says you should intervene and when you need to take a step back.