Can You Kiss the Deceased?
Question

Many relatives and friends of the deceased kiss him. Is there any Sunnah regarding that? May his wife kiss him or not?
Praise be to Allah.Is it permissible to kiss the deceased?
The authentic Sunnah indicates that it is permissible to kiss the deceased after death , whether he was a relative or otherwise. It is permissible for men to kiss the deceased man, and it is permissible for women to kiss the deceased woman. 
`Aishah (may Allah be pleased with her) that the Prophet (blessings and peace of Allah be upon him) kissed ‘Uthman ibn Madh`un after he died, and he wept… (Narrated by Abu Dawud, 3163; classed as authentic by Al-Albani in Sahih Abu Dawud.)
`Aishah (may Allah be pleased with her) narrated that Abu Bakr As-Siddiq (may Allah be pleased with him) kissed the Prophet (blessings and peace of Allah be upon him) after he died. (Narrated by Al-Bukhari, 4457)
An-Nawawi (may Allah have mercy on him) said: “It is permissible for the family and friends of the deceased to kiss his face, and there are proven Hadiths that speak of that." (Sharh Al-Muhadhdhab, 5/111).
Ibn HAjar (may Allah have mercy on him) said: “This Hadith indicates that it is permissible to kiss the deceased…”
Ash-Shawkani (may Allah have mercy on him) said: “That is because there is no report to suggest that anyone of the Companions objected to Abu Bakr doing that, so there was consensus on that matter.”
Can a wife kiss her husband after death?
Similarly, there is nothing wrong with the wife kissing her husband after he has died .
Shaykh Ibn Baz (may Allah have mercy on him) said: “There is nothing wrong with kissing the deceased, if he is kissed by one of his female Mahrams, or by a man, as Abu Bakr As-Siddiq (may Allah be pleased with him) did with the Prophet (blessings and peace of Allah be upon him)." (Majmu‘ Al-Fatawa  13/102).
For more details, please see the following answers: 155045 , 14016 , 4022 , 157925 , and 9942 .     
And Allah knows best.