At university today, a bunch of people told me that if you touch someone who is not known/related to you (na mehram) other than your father, brother etc. your fast is broken. What truth is there to this? I am pretty sceptical since this is the first time I have ever heard of something like this.
Anyone knows if there is any truth to this?
No your fast is not broken. But its haram to touch a ghayr-mahram.