Belle, 51, was arrested after cops got a call around 9:20 PM reporting a man had exposed himself to a group of people at the Phoenix Rising Soccer Club stadium -- where a game had been played.

It's unclear if the alleged incident occurred inside or outside the stadium.

When cops arrived, they say they located Belle in a vehicle ... attempting to leave the soccer stadium parking lot.

After investigating, Salt River PD determined there was enough probable cause to arrest Belle -- and another adult male.

Belle's charges include 3 counts of indecent exposure and DUI.