1H is a group. A group of friends that always stick together through the good and the bad times.
1H is a place you can feel safe and relaxed. Sure, you might be made fun of in the group but you’ll also make fun of someone else. There are no hard feelings in this group, just love and friendship.
Comes from deviantart, where notices known as "hot topics" are labelled as "H" in your messages. They're almost always completely uninteresting, lame promotions, and a total waste of time.
"You dragged me out here for this? Dude, you 1H'ed me!"