A female football player got her boob straight-up YANKED in an LFL game ... and was HEATED when she didn't get a penalty called for it. It all went down last month in a May 11 matchup between the Chicago Bliss and the Los Angeles Temptation -- when Bliss safety Alli Alberts had her boob, um, held…

One of the biggest stars in the Legends Football League is upset she's been BANNED from dating an opposing player ... but the head of the league tells TMZ Sports ... the rules are the rules. Multiple sources tell us ... the woman at the center of the controversy is Alli Alberts -- a star WR for…