7:43 AM PT -- TMZ Sports has obtained Brown's countersuit in which he spells out his side of the story ... down to the graphic details. We'll hit these one by one ...
-- AB's attorney says point-blank, "Brown did not rape Taylor, nor did he exert physical force upon Taylor. Taylor and Brown had a consensual sexual intercourse on May 20, 2018."
The doc continues, "At all times, Taylor conveyed to Brown her willingness to engage in consensual sexual intercourse."
-- The Back Incident ...
Taylor had claimed in her lawsuit that Brown creeped up from behind her while she was watching a church video in 2017 and ejaculated on her back without consent.