2,247. Embracing Relatives
Hilchos Issurei Biah 21:6
If a man hugs or kisses any woman prohibited to him as a forbidden relation even though his heart doesn’t desire her – like an adult sister, his mother’s sister, etc. – it’s a shameful matter, both prohibited and foolish. This is so even if he derives no pleasure at all from it because a man shouldn’t show affection to a woman prohibited as forbidden relation, neither an adult nor a minor, except for a woman and her son or a man and his daughter.
Hilchos Issurei Biah 21:7
Pursuant to the previous halacha, a father is permitted to hug his daughter, kiss her and sleep with their bodies touching; a mother may do likewise with her son. This is the case when they’re young. When they grow and the girl starts to develop, then they must sleep in clothing. If the girl is embarrassed to stand naked in front of her father or if she married, or if the woman is embarrassed to stand naked in front of her son, then even when the children are young, when one reaches the point of embarrassment in front of them, they may only sleep together clothed.