A-Mei’s bartender boyfriend posted a pic of their toothbrushes to mark her 51st birthday; what does it mean?

Could this be a sign that Taiwanese pop diva A-Mei and her bartender boyfriend, Sam Yao, have decided to become more public with their relationship?
On August 9, A-Mei turned 51, and this was what Sam posted on Instagram.
Yes, a picture of two toothbrushes.
In his caption, Sam revealed he had received a request to post a picture of him and A-Mei. His reply was 'Yes' and proceeded to post that pic.
Fans joked that A-Mei and Sam “really resemble each other” and that they have a serious case of “couple face”.
The pic also revealed that A-Mei and Sam are probably living together or stay over at each other's house often at least.
The couple has always been low-key about their relationship.
Sam once took to the stage during A-Mei’s New Year concert in Taitung as a DJ, and has been accompanying A-Mei on tour this time round too.
However, they’ve refrained from posting pictures of each other, which is why this simple picture of two toothbrushes got fans so excited.

Photos: Sam Yao/Instagram, A-Mei/Instagram