Jan Shane is furious with the Rolling Stones rocker after it emerged he met his new lover Melanie Hamrick - who he was pictured embracing on a hotel balcony in Zurich, Switzerland, on June 1 - weeks before the fashion designer's suicide in March, and she is now convinced his womanising played a ''bigger part'' of her younger sibling's problems.
Jan said: ''The more I think about it, the angrier it makes me. My sister deserves more respect.
''It hasn't even been three months since she died. I now believe that he was a bigger part of her troubles than we knew about.
''It doesn't surprise me at all. I'm just really glad that L'Wren doesn't have to put up with him any more.''
Jan, 53, went on to slam the 'Paint It Black' star's ''sad'' antics and the speed in which he has moved on from his later partner of 13 years.
She added to the Daily Mirror newspaper: ''My sister deserved so much more than that. It's a terrible thing for Mick to have done. It's sad. His life goes on as if nothing happened. He's still out with women, but a huge part of our family is missing.
''She had accomplished so much without him. She was amazing in so many people's eyes. He just needs to quit dragging her name through his c**p!''
It was revealed yesterday (15.06.14) that Mick, 70, met Melanie backstage at one of his gigs in Tokyo, Japan, on March 6 - just 11 days before L'Wren hanged herself in her New York home.
Insiders say the rocker made a ''beeline'' for their dancer - who was previously engaged to a man 20 years older than her - but they did not ''consummate their friendship'' until the recent trip to Zurich.
Mick - who has seven children from previous relationships - spent Father's Day yesterday in Vienna, Austria, with some of his children and ex-wife Jerry Hall.
There's still no reunion planned though.