Mama June -- By-the-By ... I'm Bisexual!

Mama June wants the world to know ... "I'm bisexual."

The "Here Comes Honey Boo Boo" matriarch tells TMZ she had 3 experiences with women in her life but says, "It's no big deal, I was young and experimented with it, never went pro though just played the minor leagues."

While she and Sugar Bear are currently broken up, June says she is working things out with him. But if they don't get back together ... "It's open season. I will keep ALL my options open."

Standby ladies (and guys) ... Mama's about to run wild.