A lot more than a win was on the line when Ka'imi Fairbairn nailed a 59-yard field goal to help the Houston Texans beat the Buffalo Bills on Sunday ... 'cause one die-hard fan vowed to free the nip if her team came out on top -- and she stayed true to her word!!
X user @sourpatchkidsx made the X-rated promise during the first quarter of the matchup ... when C.J. Stroud and Co. held onto a 7-3 lead.