FAT 肥

My colleague and I were having bathroom chat.
我和一个同事在厕所里三八。
We chat about nonsense....
聊些有的没的。

Out of the sudden, "Hi, you are more filling now! Your pants are tighter now!"
刹那间，"嘿，你好像比较肉肉了耶! 看，连裤子都紧了!"
"....." What am I supposed to answer?
"呃..." 我该如何回答才好喔?


Am I categorized as FAT already?
难道，我已经被列为肥胖组了?