三分热度却囍你好久
[sān fēn rè dù què xĭ nĭ hăo jiŭ]
'A passing fancy but I have liked you for a long time.' This suggests that while it might seem like just a fleeting infatuation, the person has had deep feelings for someone else for quite some time. '囍' is an artistic variant of the character for 'happiness,' emphasizing positive emotions.