(1) The Book of Purification and its Sunnah
كتاب الطهارة وسننها
(97) Chapter: The sexually impure person warming himself with his wife before she bathes
(97) باب فِي الْجُنُبِ يَسْتَدْفِئُ بِامْرَأَتِهِ قَبْلَ أَنْ تَغْتَسِلَ ‏
Sunan Ibn Majah 580 
It was narrated that 'Aishah said:
"The Messenger of Allah used to have a bath to cleanse himself from sexual impurity, then he would warm himself with me before I had the bath."
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا شَرِيكٌ، عَنْ حُرَيْثٍ، عَنِ الشَّعْبِيِّ، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ يَغْتَسِلُ مِنَ الْجَنَابَةِ ثُمَّ يَسْتَدْفِئُ بِي قَبْلَ أَنْ أَغْتَسِلَ ‏.‏
Grade :  Da'if (Darussalam)
Reference : Sunan Ibn Majah 580
In-book reference : Book 1, Hadith 314
English translation : Vol. 1, Book 1, Hadith 580