Hatfields vs. McCoys, Capulets vs. Montagues, Bloods vs. Crips, Democrats vs. Republicans, Kansas University football players vs. KU basketball players.

The credibility of all that happy talk about the Kansas University athletic department being one big, cuddly family has been called into question by football players and basketball players getting into repeated fights with each other.

Bar owners and patrons know it. Students know it. Cops know it. The only reason you haven’t read more about it is because precise details of said skirmishes have been difficult to nail down.

Funny how athletes who can be such men during competition, putting their bodies in harm’s way, giving everything they have for teammates, can turn into such children when trying to prove their machismo off the field.

It’s time for them to call a truce and grow up because the alternative could be blowing up football and basketball seasons that have such exciting promise. The student-athletes who can’t seem to keep their fists off of each other are running the risk of ruining experiences that could be the most enjoyable of their lives.

Tuesday’s fight — not the first pitting basketball players against football players — happened shortly after 6:30 p.m. in front of Burge Union and reportedly involved a dispute over a woman who used to date an athlete from one team and now dates one from another. Instead of letting lovers be lovers, fighters had to prove they’re fighters. How pathetic. Time to grow up and join the real world.

Fights are not altogether uncommon between teammates in professional sports, the most famous tending to be in major-league baseball.

In 1978, Don Sutton and Steve Garvey went at it on the floor of the visiting clubhouse at Shea Stadium, clawing each other. Sutton came out of it with a bruise on his cheek, and Garvey had cuts on his face. They never became pals, but managed to remain teammates.

Twelve years later, Cubs Marvell Wynne and Shawon Dunston rolled around on the ground, exchanging claws and punches outside the home dugout before a game. Dunston suffered a strained shoulder, and Wynne received three stitches on his forehead to close a cut. Both former players are African-American, and the fight started when one said to the other, “You’re not black. You’re too black to be black. You’re purple.” They shook hands and co-existed peacefully from that point forward.

Figure skater Nancy Kerrigan was rapped on the knee by a man swinging a tire iron. Classy Tonya Harding insists to this day she had nothing to do with it. Not only that, she makes that claim with a straight face.

One-on-one disputes are bad enough, but when members of the two most prominent teams at a university repeatedly have team members getting into it with each other, that’s a serious problem that needs to be addressed in a serious way.

Suggestion: Athletic director Lew Perkins invites the police chief to join him in paying one visit to the assembled football team, another to the basketball team. Let them all know a no-tolerance policy is in effect, and anybody who has a hand in breaking the truce will get one phone call and be served bread and water.