I asked the Messenger of Allah ﷺ, "What about a man who has intercourse with his wife but does not ejaculate?"He replied, "He should wash whatever part of him touched the woman, perform ablution, and pray."
حدثنا يحيى بن سعيد أخبرنا هشام بن عروة أخبرنا أبي
سألت رسول الله ﷺ قلت الرجل يجامع أهله فلا ينزل قال يغسل ما مس المرأة منه ويتوضأ ويصلي
Its isnad is sahih. Its narrators are well-known imams. The hadith was narrated by Bukhari 1/398, no. 293, in Fath al-Bari, in the chapter on ghusl, on washing what touches a woman's private part, and by Abdul-Razzaq 1/249, no. 957, in the chapter on purification, on what necessitates ghusl, and by Bayhaqi 1/164.