Here's a story behind The Bachelor you'll never see on TV.

The first Bachelor, Alex Michel -- who snubbed Bachelorette Trista Rehn for a younger woman at the end of the first series -- continued to carry a torch for Trista, writing and phoning her for months after the show ended.

And when the girl Alex had picked on national TV, Amanda Marsh, learned about his double-dealing, she left Alex, according to a sizzling report in the upcoming issue of TV Guide.

So how lucky is Trista that she was not the girl Alex picked?

Very lucky, according to the Nielsen ratings, which indicate that Trista is a huge hit as the star of the new show, The Bachelorette, which debuted Wednesday night with top-drawer ratings. A staggering 17.4 million viewers watched the first episode, steamrolling over an original episode of NBC's The West Wing.

Now Trista is telling the story of how Alex came down with a bad case of buyer's remorse almost immediately after proposing to the other woman.

Last May, "basically he told me that he thought he had made a mistake," she tells TV Guide.

Alex and Trista conducted a sort-of secret relationship from there, as he dogged her with letters and repeated phone calls -- even though he was in Los Angeles living with Marsh.

"He'll probably deny that he said [that he'd made a mistake], but that's the reason I continued to correspond [with him]," Trista says. "Going by what he told me, I didn't see anything wrong" with writing to him.

When TV Guide contacted Alex for comment, he replied: "I don't have one."

Trista says she broke off the correspondence with Alex for several reasons.

For starters, her family and friends didn't like him, telling her she'd "lucked out" by losing to Amanda.

Even Amanda seems to agree with that assessment, telling TV Guide that, when she watched The Bachelor finale on TV, she couldn't believe her eyes.

"Alex was on the air, telling Trista she could be the one. And I was like, 'Are you kidding?' " Amanda told the magazine

Trista says she was also upset when she saw Alex and Amanda at last May's Kentucky Derby. Even though she says she still "really wanted to be with Alex," she began to question her attachment to him.

When Amanda discovered that Alex had been talking and writing to Trista behind her back, she caught the first plane back home to Kansas, the magazine reports.

Meanwhile, Rehn's turning-the-tables role on The Bachelorette paid huge dividends for ABC. Not only did the show swamp The West Wing by 3.4 million viewers, but it snagged the coveted adults 18-49 demo for the night.

All of that still wasn't enough, however, to top the week's other big reality show debut -- Fox's Joe Millionaire, which grabbed 18.6 million viewers this past Monday.