Nick Lachey -- a HUGE Cincinnati Bengals fan -- was escorted out of the stands at the San Diego Chargers football game this weekend ... after security decided his TRASH TALK crossed the line.
It's unclear exactly what Nick said to piss off stadium security ... but after he was ejected, the former boy-bander actually BRAGGED about getting the boot, tweeting: "Just got kicked out of the chargers stadium and couldn't be prouder! Go Cincy Bengals."