Touching Relatives
Question
Can male relatives hug and kiss female relatives at family get-togethers?
Answer
Shalom!
Thank you for your question.
It is forbidden to touch, hug, and kiss members of the opposite gender including relatives. According to some authorities doing so may even be a Torah prohibition.
One is only permitted to hug and kiss one’s mother/father, son/daughter, grandson/granddaughter. Kissing a sister until the age of 3 is allowed and a brother till the age of 9. One may not touch, hug, or kiss uncles/aunts, sisters in law/brothers in law, cousins etc.
One is advised to let relatives know in advance that one does not touch members of the opposite gender.
Source
Rabbeinu Yona, Igeres Hateshuva 1:11; Rambam Sefer Hamitzvos 353,Issurei Bia 21:7; EH 21; Chochmat Adam 125.