OHHHHHHHH SNAPPPPPPP: FLOYD'S BABY MAMA Outraged Over 10-Year-Old Daughter's Fight Outfit!

Floyd Mayweather Jr.'s baby mama is LIVID -- telling TMZ, her 10-year-old daughter was dressed up like some gold-digging hoochie at the big fight on Saturday ... and it's all one designer's fault.

The designer in question is Project Runway's Michael Costello -- and Floyd's baby mama Josie Harris tells us, Costello was hired to design a very special dress for the boxer's 10-year-old daughter Jirah to wear at the Canelo fight in Vegas (left).

Josie says the dress came out great -- but when they showed up to the fight, she noticed Floyd's on-and-off-again side piece Shantel Jackson wearing the same exact dress (right).

According to Josie, she paid Costello $795 for a one-of-a-kind dress, and now she's pissed the guy gave a replica to none other than Floyd's girlfriend ... who also sat ringside.

Josie tells us, "It's an unspoken rule and a cardinal sin for a 'real designer' to dress clients alike going to the same major event ... Tacky, tacky, tacky."

And Josie didn't stop there, turning her anger toward Jackson as well ... adding, "She is a total gold digger ... She conveniently came back around 2 days before Floyd got his $41.5 million check."

As for the designer, Costello says he will NOT be giving anyone a refund -- telling us, "No exclusivity was promised regarding the dress. If you want exclusivity, you need to pay more." Costello says his people told Miss Jackson that Floyd's daughter would be wearing the same dress and she didn't care.

OK: 1ST OF ALL IF ANYTHING I THINK THAT DRESS FOR THIS LITTLE 10YR OLD GURL IS TO SEXY FOR A KID. SO WHY WOULD JOSIE GET THAT DRESS MADE 4 HER DAUGHTER & WHAT THE HELL MISS. JACKSON BEING A GOLD DIGGER HAS TO DO W/THE DRESS SITUATION, AND I'M QUITE SURE MISS. JACKSON DECIDED TO WEAR THE DRESS FOR THE SOLE PURPOSE OF HER & HER STEP-DAUGHTER TO DRESS ALIKE & I THINK THAT WAS "ADORABLE". LETS KEEP THINGS ALL THE WAY REAL, JOSIE IS ONLY UPSET ABOUT 2 THINGS. THAT FLOYD WOULD NEVER PUT A RING ON HIS BABYMAMA WHOM IS DEEPLY IN LOVE W/FLOYD, BUT HE DOESNT FEEL THE SAME WAY ABOUT JOSIE. SO JOSIE IS EXTREMELY JEALOUS AT THE FACT THAT, MISS. J; IS GORGEOUS, HAS A RING ON IT, REPLACED JOSIE, LIVES W/FLOYD, IS PLANNING 2 MARRY FLOYD, AND IS THE STEPMOM TO FLOYD'S KIDS. WE ALL KNOW FROM THAT TLC SHOW THAT GOT CANCELED CALLED, "STARTER WIVES CONFIDENTIAL" THAT FLOYDS "BM" WAS ON THAT JOSIE IS CRAY CRAY IN REAL LIFE. THIS BEOTCH HAS: A DRINKING PROBLEM, IS HEAD-OVER HILLS IN LOVE W/A MAN THAT HAS CLEARLY MOVED ON (AND THAT FxxkS HER WHENEVER HE FEELS LIKE IT, THEN GOES BACK HOME 2 HIS GORGEOUS FIANCEE, MISS. J), HAD 3 KIDS BY FLOYD & THEY NEVER BEEN MARRIED (I'M SORRY BUT IF I STARTED OUT W/YO AZZ FROM THE BOTTOM, UP. I MIGHT HAVE 1 CHILD W/THE MAN I LOVE, BUT TRUST & BELIEVE IT SURE WON'T BE NO BABY #2 UNTIL U PUT A RING ON IT AND DEF WHEN HE BECAME FILTHY RICH. OH YEA, BABY #3 WE WOULD DEF B MARRIED NO DOUBT ABOUT IT) GOT HER AZZ BEAT BY FLOYD & GOT HIM LOCKED UP, THEN STILL WENT BACK. KNEW HE HAD A GIRLFRIEND, BUT STILL FxxKS & WILL ALWAYS BE "JUS THE BABY MAMA" & AN "IDIOT" FOR JUMPING WHENEVER SHE GET THAT CALL, BUT NEVER GETTING WHAT SHE WANTS OUT OF FLOYD. LIKE A RELATIONSHIP, OR EVEN MONEY (IM NOT SAYING FLOYD IS A DEADBEAT AT ALL, HE'S OBVIOUSLY A GREAT FATHER, BUT IF IM GONNA BE JUMPING WHENEVER U TELL ME TOO. MY AZZ DEF WILL BE GETTING MORE THAN JUST CHILD SUPPORT OUTTA HIS RICH AZZ, CAUSE IF U CAN CONTINUE & I ALLOW U TO USE ME AS A; REBOUND, SIDE-CHICK, FRIENDS W/BENEFITS, FxxKING BUDDIES, WHATEVER U WANNA CALL IT. TRUST AND BELIEVE THIS PxxxY WILL DEF BE COSTING....ALOT). SHE KEEPS ALLOWING FLOYD TO BREAK HER HEART INTO A MILLION PIECES, BUT TRUST & BELIEVE THAT "A MAN CAN ONLY DO, WHAT U ALLOW THEM TO DO". AND THESE ARE THE REASONS WHY JOSIE A.K.A "BM" A.K.A "THE BABYMAMA". SO CUT THE DAM CRAP JOSIE, U DONT GIVE A SHITZ ABOUT NO DAM DRESS THAT A 10YR OLD LITTLE GURL SHOULD BE WEARING ANYWAYS, LETS BE ALL THE WAY REAL. YOUR JUST UPSET THAT "THE MAIN CHICK/WOMAN" A.K.A "THE FIANCEE" A.K.A "YOUR KIDS STEP-MOM" A.K.A "MISS. JACKSON" ALIAS: SHANTEL JACKSON A.K.A THE WOMAN THAT JOSIE WISH SHE COULD BE, IS ACTUALLY WEARING THE EXACT DRESS AS HER STEP-DAUGHTER TO HER FIANCEES FIGHT. AND NORMALLY WHEN U SEE A ADULT & KID WEAR THE DAME OUTFIT OUT SOMEONE WHERE THEIR SEEN TOGETHER, IT MAKES PEEPS AUTOMATICALLY BELIEVE THAT ITS MOTHER & DAUGHTER. AND THE FACT THAT ITS THE STEP MOM THAT JOSIE HATES & IS JEALOUS OF, IS BEING SEEN BY THE WORLD W/THE SAME OUTFIT AS HER STEPDAUGHTER & MISS. J BEING HATED BY JOSIE, OBVIOUSLY MAD JOSIE FURIOUS. SHE FEELS AS THOUGH, WHY THE FxxK IS THIS BEOTCH WEARING THE SAME OUTFIT RIGHT ALONG MY CHILD, TO MY BABY-DADDY'S FIGHT, MAKING PEEPS THINK THAT SINCE THEIR DRESSED ALIKE. THAT OBVIOUSLY, MOTHER DECIDED TO DRESS HER DAUGHTER TO MATCH MOMMY (BUT SHES NOT THE MOTHER, AND I CAN SEE HOW THIS COULD HURT A MOTHER). LOOKING AT IT FROM A MOTHERS PERCEPTIVE, U ALREADY JEALOUS OF UR KIDS STEP MOM WHO U HATE TO DEATH, THEN U FEEL LIKE SHES INTENTIONALLY TRYING TO REPLACE U BY ACTING AS IF SHES UR KIDS REAL MOTHER, WHICH SHE ISN'T. BUT ITS JUST CAUSE JOSIE HATED MISS.J'S GUTS CAUSE OF HER BEAUTY, THAT SHES THE FIANCEE & JOSIE ISN'T, CAUSE HER KIDS WHEN W/THEIR DAD, IS ALSO TAKING CARE BY MISS. J, SO JOSIE'S FEELINGS PROBABLY WAS HURT. DEF SINCE SHE HAD NO IDEA THAT MISS. J WAS PLANNING ON GETTING A DRESS CREATED FOR HER TO INTENTIONALLY TO MATCH HER STEP-DAUGHTER, AND OBVIOUSLY FLOYD WAS IN ON IT & OK WITH IT. AND STEP MOM & STEPDAUGHTER ACTUALLY LOOKED SO ADORABLE. BUT IN GENERAL JOSIE'S WRONG FOR PUTTING THAT DRESS ON HER 10YR OLD DAUGHTER, FLOYD SHOULD HAVE WARNED JOSIE 1ST, MISS. J NEEDS TO PUT INTO CONSIDERATION HOW HURTFUL THAT CAN BE TO A MOM, DEF WHEN U FIND OUT THAT THE WOMAN U DESPISE IS GOING TO SHOW THE WORLD HER LOVE FOR HER "SD" BY BEING ADORABLE W/MATCHING DRESSES. JUST ATLEST ASK THE MOM, CAUSE MOMS SOMETIMES FEELS AS THOUGH THEIR BEING REPLACED DEF WHEN THE KIDS ACTUALLY LOVE THEIR STEP-PARENTS, IT MAKES PARENTS FEEL LIKE THEIR BEING REPLACED. BUT AGAIN, WE ALL KNOW THAT JOSIE IS LITERALLY A TRAIN WRECK & ITS MOSTLY BECAUSE OF HER THE LOVE SHE HAS FOR FLOYD (AND THE "D" WILL ALWAYS HAVE U WHIPPED INTO CRAZINESS WHEN ITS GOOD. BUT JOSIE  HAS ALOT OF PROBLEMS THAT SHE NEEDS TO WORK ON FOR HERSELF, NOW I SEE WHY THE KIDS LOVE MISS. J CAUSE SHES SO SWEET & KIND, AS WELL AS FLOYD ALWAYS HAVING HIS KIDS MORE THAN JOSIE DOES. AND THAT'S GOOD, CAUSE JOSIE (NOW ON A SERIOUS NOTE, NO PLAYING AROUND) NEEDS SOME TYPE OF THERAPY & NEEDS TO DATE AS WELL TO FIND A MAN OF HER OWN AND NOT ONE THAT BELONGS TO OTHER WOMEN. JOSIE MOVING ON & NOT BEING A REBOUND/BOOTY CALL, WILL ACTUALLY SOLVE ALOT OF HER PROBLEMS NOW. I MEAN IF SHE WANT SO IN LOVE W/FLOYD SHE COULD: MOVE ON W/HER LIFE & SHARE IT W/SUMONE WHO WANTS HER JUST AS MUCH AS SHE WANTS HIM, STOP BEING AN ALCOHOLIC (SHE DRINKS BECAUSE OF HER PROBLEMS W/FLOYD), SHE WOULDNT HAVE TO GET INTO VOLATILE ARGUMENTS ANYMORE, SHE WONT BE DEPRESSED & CAN ACTUALLY ENJOY LIFE & HAVE; HAPPINESS, PEACE & JOY!