Lindsay Lohan’s new boyfriend, a 24 year-old snowboarder who rose to instant notoriety when squiring the drama queen around Sundance, Utah, had a fiance he unceremoniously dumped shortly after he started fooling around with Lohan.

Breanna Tierney told the National Enquirer that she met Lohan at an AA meeting she attended with her fiance, and that Lohan was overly nice to her and tried to suck up, complimenting her hair and clothing. She had lived with her fiance Riley Van Giles for three years at that point and was immediately suspicious of how fake nice Lohan was acting towards her.

Yesterday the NY Daily News reported that jilted fiance Bree’s mother told US Weekly that Riley broke up with her daughter using the old passive aggressive method of not returning her phone calls, but by Bree’s account it was worse than that. Riley texted her that he “needed a break” and eventually confessed that he’d screwed Lohan in one of the stairwells at rehab:

“I loved Riley and Lindsay stole him. I met her at a meeting while they were still patients at Cirque, and I just knew something was up.

“She came into the meeting with Riley, and she comes over and sits next to me, being overly nice. She was complimenting me on my hair and trying to be my friend. It didn’t seem sincere at all.

“A few days later, I get a text message from Riley telling me he wanted to ‘take a break.’ I knew instantly it was because of Lindsay.”

The distraught 22-year-old — who supported Riley through numerous busts and his struggle with drug addiction — says he got on one knee and proposed to her almost three years ago.

“I’ve stuck by Riley through the good and the bad,” Breanna told The ENQUIRER. “We lived together for three years and planned on being together forever.

“But when he finally confessed to me that he had sex with Lindsay in one of the stairwells at Cirque — that was it, we were done.”

[From The National Enquirer]

Plus Riley was so cheap that he gave Bree a cubic zirconia engagement ring and acted like it was a diamond. She brought it to the jeweler to replace some “diamonds” that had fallen out and was told it was a fake.

Meanwhile Lindsay and Riley have gone to In Touch to tell their version of the story, which is of course more favorable to Riley. They claim that Riley had broken up with Bree a week before they hooked up in rehab, and that he was never engaged to her. Riley claims he was only with Bree for two years, not three:

“We started out as friends,” explains Lindsay, who sat down for an exclusive interview with In Touch in Utah. “We met about two months ago while doing activities at Cirque. We both enjoyed rock climbing,” she says. Their romance started slowly, says Lindsay, 21. “We waited until we were both out of treatment because it made more sense.”

Riley, 25, a professional snowboarder who is remaining in Utah, had been dating a girl named Bree Tierney when he met Lindsay, but he denies that Lindsay caused their split. “I broke up with Bree a week before I started dating Lindsay,” he told In Touch. “We had dated for almost two years, but it’s not like we were engaged or anything.”

[From In Touch]

Lohan, who hasn’t been seen out at a bar or club in the week she’s been back in LA, says she’ll continue the long distance relationship that we’re all betting against, and that she’ll “probably go to Utah on a weekend and he will hopefully come to visit me in LA.”

And Riley wasn’t in rehab for nothing. Yesterday two mug shots of the guy were released. It turns out he has a rap sheet that includes forging prescriptions and DUI, for which he spent 10 days in jail. He’s perfect for Lindsay, and it’s so convincing when they join forces to lie to the tabloids. I give it two more months before he kicks Lohan to the curb, realizing that the fame and money just aren’t worth the hassle. That’s about as long as Harry Morton lasted, but he did get a lot of free publicity for his taco chain out of the deal. Maybe Riley will come away with a lucrative endorsement contract.

Note: The NY Daily News reported yesterday that Riley is 25, while The National Enquirer has his age at 24. It doesn’t make a big difference, I just wanted to point it out in case you noticed.

Lohan is shown leaving a dance studio carrying CDs on Tuesday in the image accessible below and after getting her hair done at Ken Pave’s salon in the header photo. Thanks to Splash News.

Thanks to The National Enquirer and In Touch for the two inset photos.