Toni Tennille insists she never cheated on her husband and longtime musical partner — despite being trapped in a loveless marriage for nearly 40 years.

“The only one I slept with the whole time I was married was Daryl,” she told FOX411. “I was determined I was going to make my marriage work.  I also made a vow that I was going to be true to Daryl and faithful to Daryl, and I was the entire time.”

The Captain & Tennille, Toni and husband Daryl Dragon, topped the music charts in the 1970s with hits including “Muskrat Love,” “Shop Around” and “Love Will Keep Us Together.”

In her new memoir, “Lost In The Circle,” the singer reveals that A&M Records basically forced the duo into marriage in 1975 by issuing a press release saying that they had wed on Valentine’s Day.

“Of course they neglected to say anything to us about it,” she writes.  “So it wasn’t until fans began mentioning it in their letters that we learned our record label had ‘married’ us.”

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Their real wedding took place a few months later a tiny chapel at the Silver Queen Saloon in Virginia City, Nevada.
Tennille, 75, filed for divorce in 2014 after many years of “soul searching.”

She is now content to spend the rest of her life alone.

“I have got my dog and I have the love of my family — my sisters and my nieces,” she said.  “I don’t have that kind of [romantic] love and I will never have it.  That is just what happened to me in this life.  I don’t think I want to find it, and I don’t think I could anyway.”

Tennille said her marriage to Dragon was lonely.

“I think that is kind of late to go looking for somebody else.  Besides, even though Daryl and I were together all those years, I was kind of on my own and lonely for a long time.”

Tennille shared more details with FOX411.

FOX411: How does Daryl feel about you exposing the dirty laundry?
Tennille:
I don’t call it “dirty laundry.” I call it truth. Fact. He is okay with it.

FOX411: Has he read your memoir?
Tennille: Not yet. I said, “Do you want me to tell you more about what it is all about?” And he said, “No.  You have always been a straight shooter, so go ahead and say what you need to say.” He is a difficult man. I tried for a long, long time. But when you get to be close to my age, you have to really make serious decisions. I lived a long time without love because Daryl just wasn’t capable of it-- couldn’t do it.

FOX411: Was there ever a time when your marriage worked?
Tennille: No.

FOX411: Was there ever a time of intimacy?
Tennille: Yes there was — and that is as far as I will go. There was a good night or two, but it was physical, strictly. There was no emotion. You know what I am saying?

FOX411: So what are you doing [these days]?
Tennille: I live in Florida. My sister Jane is a mile and a half away. I have a lot of family here. I don’t do “social calendar” stuff, but I go out with a very tight knit circle of friends. That is the way I prefer it. Believe me, I don’t sit in my house all the time. I know it doesn’t sound like it, but I am happy. I talk to Daryl regularly. About every two weeks we chat. He is OK.

FOX411: Where is he?
Tennille: He is in a cottage, a very lovely place on the other side of Prescott, Arizona, from where I used to live. He has people who do things for him. I used to be the one who did it. It is really hard to explain. He is a very difficult man. He always has been, but that was part of the situation. The thing we did do well together — the thing we did best — was music, and that was really the only thing that worked.  

FOX411: When you look back on the 40 years you had with Daryl and everything you had to sacrifice to achieve stardom and financial success, was it worth it?
Tennille: Yes, it was. When Daryl and I were working together, even though I didn’t get the nourishment or the love, it was the most creative I have ever been. I was just filled with songs, and I couldn’t wait to get out there and do. That is what I loved. I loved the music. Because of Daryl and our working together, I was able to get out there and do that. That was my joy and still is.