The Messenger of Allah ﷺ happened to meet him and he was (sexually) defiled, and he slipped away and took a bath and then came and said: I was (sexually) defiled. Upon this he (the Holy Prophet) remarked: A Muslim is never defiled. (Using translation from Muslim 372)
أَنَّ رَسُولَ اللهِ ﷺ لَقِيَهُ وَهُوَ جُنُبٌ فَحَادَ عَنْهُ فَاغْتَسَلَ ثُمَّ جَاءَ فَقَالَ كُنْتُ جُنُبًا فَقَالَ إِنَّ الْمُؤْمِنَ لَا يَنْجُسُ