Sean Lowe is basically the all-American male. He has traditional values, he's a virgin and he lies about those first two things to impress people -- particularly people who watch 'The Bachelor.'

Multiple sources have told Life & Style that the self-proclaimed "born again virgin" did the dirty with fiancee Catherine Giudici while the show was still taping, even though he's said publicly the pair is waiting until after the wedding to get bizzy.

“Yes, they definitely had sex,” says an insider, who claims the first time was the night Sean proposed in Thailand.  After that night, the two allegedly had to meet on the down-low for secret, late-night trysts in Los Angeles until the finale aired.

“Catherine has always respected Sean wanting to show his Christian side, but she honestly would never marry him without making sure they had sexual chemistry,” says the source. And as for Lowe's alleged virtue: “It’s all for the show and his parents."

A separate insider told the mag that "the whole born-again-virgin thing is a bunch of B.S. It’s just something he made up for the show.”

There's no problem with being a Christian on television, and there's no problem with two consenting adults doing whatever they want -- those two things aren't mutually exclusive. But hypocrisy sucks.

And, no, we aren't surprised that a reality television star would be a snake, but waving around a fake V-card? Even a "born again" one? Lowers the bar even more.

In case you've missed them, here are some inspirational quotes from the Book of Sean: