I knew I was spotting but decided not to use any sanitary equipment at that time. I sat on my friend's sofa, and I leaked through and stained it. Now they're really mad. AITA?

Edit: obviously anyone who did this would be a filthy c word. However, that wasn't the response to this woman by the group, why was that?

https://www.reddit.com/r/AITAH/comments/1jmo294/got_period_on_boyfriends_mattress_and_now_he_wont/?sort=new