Jordyn Woods flaunting a huge rock on her finger is a red herring, because it turns out it was just for show and she's not marrying her NBA boyfriend ... at least not yet.
Elizabeth Woods -- Jordyn's mother and manager -- tells TMZ ... the ring her daughter's wearing in her recent Instagram pics is NOT an engagement ring from Karl-Anthony Towns.
Jordyn's mom says it's simply a piece of flashy jewelry she put on for a photo shoot -- she's definitely not engaged.