听说接吻能瘦身怪不得我瘦不了
[tīng shuō jiē wĕn néng shòu shēn guài bù dé wŏ shòu bù le]
Translating this username would give 'I've heard kissing can slim me down, no wonder I don't lose weight,' which uses a humorous way to indicate that they don’t have much opportunity for romance, hence the lack of slimming kisses. A light-hearted joke about romantic activity being tied to physical appearance changes.