"The chocolates are cos I love you. The flowers are cos I'm sorry," the note read. "The Tampax are cos I'm still not really sure why I'm apologising so I guess you'll need these any day now."
The tweet got more than 27,000 likes and hundreds of replies, however, the response to the man's attempt at a funny apology was ahem, mixed.
"I hope she dumps you," one person tweeted in response.
"The way this would make me turn feral," another wrote.
"It's not an apology if you're not sure why," one tweeted.
"Awww what a lovely bit of misogyny for her to come home to," one person joked.
Others couldn't believe his apology was real and accused @SullivansTweets of making "stuff up for likes", but some said it was clearly a joke between the couple.
"Seeing so many people say that whoever wrote that note isn't a bloke but to be fair my one ex has much nicer handwriting than me," one woman tweeted.
"Obviously has banter with his bird and people are crying in the comments. I like your handwriting though," another person wrote.