A Republican senator under pressure to resign said he was entrapped in a sex sting at an airport men's room and was not aware of the bathroom's reputation as a spot to "cruise" for gay sex.

Well, I certainly am now," Sen. Larry Craig told NBC's Matt Lauer in an interview to being aired Tuesday night.

"Were you prior?" Lauer asked.

"Not at all," the senator from Idaho responded. "I go to bathrooms to use bathrooms."

Craig said it was a "tough call" when he decided not to tell his wife or children about the arrest.

"I didn't want to embarrass my wife, my kids, Idaho and my friends," Craig said. "I should have told my wife. I should have told my kids. And most importantly, I should have told counsel."

Suzanne Craig said that when her husband told her the story was about to break, "I felt like the floor was falling out from under me. And I felt almost like I was going down a drain for a few moments."

Craig, a three-term Republican, pleaded guilty to disorderly conduct in August after he was accused of soliciting sex in a bathroom at the Minneapolis-St. Paul International Airport in June.

After the matter became public, Craig tried to withdraw his plea. But a judge in Minnesota refused, saying Craig's plea "was accurate, voluntary and intelligent, and ... supported by the evidence."

On Monday, Craig appealed that ruling to the Minnesota Court of Appeals.

"I hoped it would go away," Craig said of his decision to plead guilty. "I wanted to avoid a media storm."

Craig says he is not gay, and in the NBC interview, he and his wife said their marriage was based on love. Asked by Lauer whether theirs was a marriage of convenience to cover "a gay lifestyle," Suzanne Craig responded, "I would never do that. ... That's almost like selling your soul for something."

"I love this woman very, very much," Craig said in the interview, taped at the couple's home in suburban Eagle, Idaho. "And the day I found her I fell in love, deeply in love. And that's lasted — we're heading toward our 25th anniversary."

Suzanne Craig says she believes her husband is not gay. "I honestly believe my husband has always been faithful to me in every way," she said.

Craig also discussed his relationship with Republican presidential candidate Mitt Romney. Craig was Senate liaison for Romney's campaign, a post he abandoned when the scandal became known. Romney called Craig's conduct "disappointing and disgraceful" and moved to drop Craig when the guilty plea was revealed.

"I was very proud of my association with Mitt Romney," Craig said. "And he not only threw me under his campaign bus, he backed up and ran over me again."

Craig, who had initially said he planned to resign, reiterated that he will not leave his Senate seat before his terms expires in January 2009. He has said he will not seek re-election. He said he will continue to pursue his legal options.