Cops were called to the home of Brittany Jackson's current boyfriend in Cleveland, TN around 4:30 PM ... after Haynesworth allegedly showed up unexpectedly and began yelling at both of them.

Jackson claims Haynesworth drove 2-and-a-half hours from his home in Franklin to confront them in person after making violent threats over the phone.

Once police arrived, Brittany and her boyfriend told Haynesworth to stop yelling and cussing ... but the 39-year-old ex-NFL star allegedly continued to cause a scene.

Officials say the former All-Pro defensive lineman did NOT put his hands on either Jackson or her BF ... but broke the law by posing a serious threat of causing bodily harm.

Online records show Haynesworth bonded out of Bradley County Justice Center on Tuesday and is no longer in custody.

It's not Haynesworth's first legal incident with Jackson -- they had a domestic violence incident in 2017 when the 6'6", 350-pounder claimed she "kicked (him) in the nuts."

At the time, Haynesworth also claimed he had called police on Jackson for alleged violent incidents more than 10 times during their 17-month relationship.