Jason Preston isn't the only man in Marc Jacobs' life. The gay designer would never have reached such great heights had it not been for business partner Robert Duffy.

Though he typically eschews the press, Duffy recently sat down with Fortune to discuss the makings of a multi-million dollar company. In addition to chatting about MJ's retail expansion and LVMH's majority stake, Duffy dishes on Jacobs' recent drug relapse:

Something was going on in his personal life, but I wasn't 100% sure he was back on drugs. I'd been through it a million times and I wasn't going to go through it again.

It's at Duffy's urging that Jacobs returned to rehab, a move Jacobs admits saved his life: "If it weren't for Robert, I'm sure I'd be dead by now."

From what Duffy says, he feels the same about Marc:

If the company dies, I'll live. If Marc dies, I don't know what I would do. He means so much more to me than any company.

Luckily Marc's back in action and the company continues to rake in millions.