´It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said:` "When (a man) sits between the four parts of his wife's body and exerts himself, then Ghusl becomes obligatory."
Hadith ReferenceSunan an-Nasa'i / Mention When Ghusal (A Purifying Bath) Is Obligatory And When It Is Not / Hadith: 191
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:متفق عليه