an open relationship is a when two people like eachother, but you only call it a relationship when either partners legs are spread wide open like a pterodactyl's wings. otherwise theyre just regular-ass friends.
"yo bro i heard you and aaron were in an open relationship?"
"yeaah i mean we were last night!"
"whachu mean fool?"
"i mean me and aaron had relations when i tagged that ass wide open last night. hence open relatioship."