Quran 2:14 Al-Baqarah, ayah 14 of 286

وَإِذَا لَقُوا۟ ٱلَّذِينَ ءَامَنُوا۟ قَالُوٓا۟ ءَامَنَّا وَإِذَا خَلَوْا۟ إِلَىٰ شَيَـٰطِينِهِمْ قَالُوٓا۟ إِنَّا مَعَكُمْ إِنَّمَا نَحْنُ مُسْتَهْزِءُونَ ۝١٤

2:14 And when they fall in with those who believe, they say: We believe; but when they go apart to their devils they declare: Lo! we are with you; verily we did but mock.