My guy friend Calls My Female friend a Slut, Hoe and *****. How can i deal with it?

OK so My Friend since Kinder (male) Calls my Best Friend(female) a slut, a hoe or a *****. she crys alot. I just want this all to end!! And no he has the whole 6th grader (INCLUDING THE NEW KID) calling her bad names. I feel really bad. Also They say the same thing to my other bff (female). She crys OR goes to smack or punch them. we all hate it! Then they say theyll never be cool again. Then the Next day The guy friend says Kiara/Jorin im sorry! can we just be friends. Its like they cant live with them but they cant live without them. then wen theyre friends, IT HAPPENS ALL OVER AGAIN! LIKE A MENSTRUAL CYCLE! ugh! I just really cANT Stand It! plz help!