Bubblegumgender is a Xenogender. It's defined as when one's gender feels sometimes soft and sometimes tough. The name comes from bubblegum being hard before you start chewing but when you start chewing, it becomes soft.
History
The term was coined by Twitter user kn0ckwhosthere in November 2020.
Flag
The flag was created by the same user who coined this xenogender and it is inspired by the colors that bubblegum comes in.