Abu Hurairah narrated:
"Al-Aqra bin Habis saw the Prophet (sal Allahu alaihi wa sallam) kissing Al-Hasan and Al-Husain. So he said, 'I have ten children and I do not kiss any one of them.' So the Messenger of Allah (sal Allahu alaihi wa sallam) said, 'Whoever shows no mercy, will be shown no mercy.'"[Jami At-Tirmidhi - Graded Sahih]
This shows the importance of showing affection to our children Masha'Allah.