Hazrat Sha'bi says that kissing one's wife breaks the ablution and injures the fast.

Hazrat Habib says that I asked Hazrat Abu Qilabah about kissing one's wife while fasting, so he said: Do not kiss while fasting.

Hazrat Abdullah was asked about kissing one's wife while fasting, so he replied, "What will you do about the smell of her mouth?"

Hazrat Ibn Umar (may Allah be pleased with them both) considered kissing one's wife while fasting to be disliked (makruh).

Hazrat Ibn Umar (may Allah be pleased with them both) narrates that Hazrat Umar described a dream of his: I saw in a dream that I was looking at the Messenger of Allah (peace and blessings be upon him), but the Messenger of Allah (peace and blessings be upon him) was not looking at me. I asked, "O Messenger of Allah! Why are you not looking at me?" He replied, "Do you not kiss your wife while you are fasting?" Hazrat Umar said, "By Him Who has sent you with the truth, I will never do so again."

Hazrat Muhammad bin Hanafiyyah says that the fast is invalidated by lust, and a kiss is a part of lust.

Hazrat Thalabah bin Abdullah bin Abi Sa’eer narrates that I saw the noble Companions forbidding kissing while in the state of fasting.

Hazrat Maymunah, the freed slave of the Prophet (peace be upon him and his family), narrates that the Prophet (peace be upon him and his family) was asked, "A fasting person has kissed (someone); what is the ruling?" He replied, "His fast is broken."

Hazrat Masrooq was asked about kissing while fasting, so he replied, "The night is near."