Valmiki Ramayana Ayodhya Kanda Sarga 48 Shloka 24
Original Shlokaया पुत्रं पार्थिवेन्द्रस्य प्रवासयति निर्घृणा। कस्तां प्राप्य सुखं जीवेदधर्म्यां दुष्टचारिणीम्।।2.48.24।।
1 source checked for this shloka
या that Kaikeyi, निर्घृणा unkind, पार्थिवेन्द्रस्य king's, पुत्रम् son, प्रवासयति has banished, अधर्म्याम् unrighteous, दुष्टचारिणीम् of wicked behaviour, ताम् her, प्राप्य having her (as a ruler), कः who, सुखम् with pleasure, जीवेत् will live?
Who can live with pleasure under the rule of Kaikeyi of unrighteous character and wicked behaviour, one who without compassion banished Rama, son of Dasaratha, king of kings?