Narrated Zaid bin Khalid:

I asked `Uthman bin `Affan about a person who engaged in intercourse but did no discharge. `Uthman replied, "He should perform ablution like the one for an ordinary prayer but he must wash his penis." `Uthman added, "I heard it from Allah's Messenger (ﷺ)." I asked `Ali Az-Zubair, Talha and Ubai bin Ka`b about it and they, too, gave the same reply. (This order was canceled later on and taking a bath became necessary for such cases).