Abu Ayyub reported that he had heard like this from the Messenger of Allah (ﷺ).
Sahih Muslim Book 3, Hadith 104
← Previous Hadith What is your opinion about the man who has sexual intercourse with his wife, but does not experience orgasm? Uthman said: He should perform ablution as he does for prayer, and wash his organ. 'Uthmin also said: I have heard it from the Messenger of Allah (ﷺ).

Sahih Muslim Book 3, Hadith 103 Next Hadith → The Apostle of Allah (ﷺ) said: When a man has sexual intercourse, bathing becomes obligatory (both for the male and the female). In the hadith of Matar the words are: Even if there is no orgasm. Zuhair has narrated it with a minor alteration of words.

Sahih Muslim Book 3, Hadith 105