Ibn Mas'ud used to say, “Ablution is necessary when a man kisses his wife.” Malik transmitted it.

وَعَن ابْن مَسْعُود كَانَ يَقُولُ: مِنْ قُبْلَةِ الرَّجُلِ امْرَأَتَهُ الْوُضُوءُ. رَوَاهُ مَالك