From the ever-reliable In Touch comes this report that Mary-Kate and Ashley Olsen are fighting—over business. It seems Ashley wants to be a serious businesswoman and focus on the twins' two (natch!) clothing lines, The Row and Elizabeth and James. But Mary-Kate doesn't want to give up her hard-partying lifestyle and put the companies first. So, Ashley's cut Mary-Kate off from working on the more high-end line The Row.

In Touch: Ashley and Mary-Kate Olsen, 22, have spent their whole lives in synch, and together created their clothing lines, The Row and Elizabeth and James, but an insider says their work ethics don’t match anymore — causing a serious rift in their relationship.

“Ashley really wants to be a respected businesswoman and be taken seriously,” says the pal. “MK does too, but she hasn’t been willing to give up her lifestyle and act like an adult for their job.” So Ashley has taken a drastic step: distancing her twin from the couture end of their joint fashion empire.

“Ashley came to a difficult decision. She decided that MK should not be involved with The Row,” says the insider. “She asked her sister to step back from her current responsibilities until she has her personal life together.” Instead, MK will focus on their more affordable line, Elizabeth and James, for which their roles were always less hands-on. “It’s tough because The Row was so much of Mary-Kate’s idea,” says the insider. “Mary-Kate has a unique fashion sense,” notes an insider. “I just see myself more as a businessperson,” Ashley says.