कर्मेन्द्रियाणि संयम्य य आस्ते मनसा स्मरन्। इन्द्रियार्थान्विमूढात्मा मिथ्याचारः स उच्यते ॥

karmendriyāṇi sanyamya ya āste manasā smaran indriyārthān vimūḍhātmā mithyāchāraḥ sa uchyate

Who sitteth, controlling the organs of action, but dwelling in his mind on the objects of the senses, that bewildered man is called a hypocrite.

In plain words: Krishna says a person who holds his body still but keeps thinking about pleasures is fooling himself. Such a person is a fake.