Is this a Saheeh Hadith, it doesn't sound so. The Prophet (Sallallahu Alaihi wa Sallam) never laughed only smiled, and suckling an adult person also sounds strange. Saheeh Muslim Book 008, Number 3424: Ayisha (Allah be pleased with her) reported that Sahla Bint Suhail came to Allah's Apostle (may peace be upon him) and said: Messenger of Allah, I see on the face of Abu Hudhaifa (signs of disgust) on entering of Salim (who is an ally) into (our house), whereupon Allah's Apostle (may peace be upon him) said: Suckle him. She said: How can I suckle him as he is a grown-up man? Allah's Messenger (may peace be upon him) smiled and said: I already know that he is a young man. 'Amr has made this addition in his narration that he participated in the Battle of Badr and in the narration of Ibn 'Umar (the words are): Allah's Messenger (may peace be upon him) laughed.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions. There are many Ahadith (sayings of the Prophet, peace be upon him) narrated in the Sahihain and other sources that describe the Prophet's way of smiling. According to these sources, the Prophet (Sallallahu Alaihi wa Sallam) used to smile in a manner that his front teeth would appear. In 'Zad Al-Ma'ad', Ibn Al-Qayyim (may Allah have mercy on him) said: Most of his laughter, actually all his laughter, for that matter, was to merely smile, in a way showing his front teeth. He smiled at whatever caused laughter or surprise. At-Tabarani in his 'al-Mu'jam al-Kabeer' and Al-Baihaqi in his 'Shu'ab al-Eman', narrated about the description of the Prophet (Sallallahu Alaihi wa Sallam) that: Most of his laughter was smiling. [Ruled as authentic by Imam Ibn Hajar in his 'Fath al-Bari'] For more details, please read Fatwa: 83159. Allah knows best.