All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is lawful for both the father and his daughter to kiss each other. This is even a Sunnah. ‘Aa’ishah narrated: “I never saw anyone more like the Prophet in respect of gravity, calm deportment, pleasant disposition (according to al-Hasan's version) in respect of talk and speech than Fatimah, may Allah be pleased with her. When she came to visit him (the Prophet) he got up to (welcome) her, took her by the hand, kissed her, and made her sit where he was sitting; and when he went to visit her, she got up to (welcome) him, took him by the hand, kissed him, and made him sit where she was sitting.” [Abu Daawood; At-Tirmithi: Hasan Hadeeth]
Another evidence is the sound Hadeeth from Al-Baraa Ibn ‘Aazib who narrated: “…I then went with Abu Bakr into his home (carrying that saddle) and there I saw his daughter, ‘Aa’ishah lying in a bed because of heavy fever and I saw her father Abu Bakr kissing her cheek and saying, "How are you, little daughter?.”
The same ruling applies to the woman and her son. It is well-known that this kissing is most of the time a way of showing affection, kindness, sympathy and compassion. But if there is fear that this kissing could lead to any kind of temptation, it should be given up to prevent any bad interpretation or bad act.
Imam An-Nawawi said about hugging and kissing: “As for hugging and kissing the face they are dislikable unless done to a child or a person who has just come from a trip or a travel.” The evidence for this is the Hadeeth narrated by At-Tirmithi and Ibn Maajah from Anas that he said: “A man said to the Prophet : “O Prophet of Allah! One of us encounters his brother or friend, does he bow for him? He said: ‘No.’ The man said: 'Does he honor him by kissing him?' The Prophet said: 'No.' Then the man said: So, does he take his hand and shake hands with him? The Prophet said: 'Yes.'”
The evidence for the lawfulness of kissing and hugging a person who is coming from a trip or travel is the following Hadeeth: At-Tirmithi reported from ‘Aa’ishah that she said: “Zayd ibn Haarithah arrived to Madeenah from a trip and came to my house. He knocked on the door. Then the Prophet stood and walked towards him while dragging his clothes (without getting prepared). Then he (the Prophet) hugged him and kissed him.”
From, the above evidence, we conclude that kissing and hugging one’s parents is lawful whether they are coming from a trip or not.
Allah knows best.