The Prophet PBUH said: ‘ For one of you to be stabbed in the head with an iron needle is better for him than that he should touch a woman who is not permissble for him.’
This hadith strictly prohibits touching non-mehrams and unfortunately many Muslims nowadays overlook this while interacting with their classmates or relatives of the opposite gender, specially cousins, husband’s brother or wife’s sister.
These are serious issues which unfortunately are taken really casually in Muslims society with the growing interaction between men and women.
Fear Allah swt wherever you are.
Your Eman is the greatest gift you have which you cannot afford to lose at any cost.