"Not all girls are great at picking up on the signs. I've missed a few, so to have an outsider who is objective to the scenario notice these signs, it just may have been a genuine warning."
Other people took the opportunity to share their own experiences of relationships gone wrong with some claiming a note would have helped them.
"I wish I'd had someone pass me a note like that when I was 18. My whole life might have been different," one woman wrote.
"I once went on a drink date and the bartender was super nice to me and kind of rude to my date. I remembered wondering if that was a red flag. Turned out it was and he was right," said another.
Someone else added: "I wish someone told me this before I got into my last relationship. Take his advice girl!"
