Spencer Pratt has accused Kaitlynn Carter of having an "emotional" relationship with Miley Cyrus while she was married to Brody Jenner.

Kaitlynn Carter

Kaitlynn Carter

The 'Hills: New Beginnings' star has claimed the 30-year-old blogger - who split from Brody in August - has claimed she cheated on him with the 'Slide Away' hitmaker.

Speaking to Cosmopolitan magazine, Spencer said: "It's tough for me to listen to Kaitlynn complain about people talking about her open relationship with Brody when we know she had a thing going with Miley. She already had something going on with [Miley] when these scenes were filming -- maybe not physically, but definitely emotionally. No one's judging you for whatever it is you and Brody do when he's not sleeping in his car. We just don't want people to lie about their lives."

People began speculating that Kaitlynn and Miley were in a relationship when they were spotted locking lips on a yacht a few days after the 'Malibu' singer confirmed that she and her husband Liam Hemsworth had gone their separate ways.

An insider said: "Miley is very close with Kaitlynn. It's romantic, but also a friendship. They are both going through similar stuff right now and are bonding over it."

The 'Wrecking Ball' hitmaker has been growing close to the influencer in recent weeks and, although it's still early days for them, they've already progressed to the next level and have moved in together.

A source said: "They live together and are very happy. Miley is doing great. She is moving on. She seems to have no regrets. She loves being with Kaitlynn."

Shortly after the photograph of them kissing went viral, Liam filed for divorce, which led to people speculating that the 26-year-old pop star had cheated on him.

Miley fumed at the time: "I can accept that the life I've chosen means I must live completely open and transparent with my fans who I love, and the public, 100% of the time. What I cannot accept is being told I'm lying to cover up a crime I haven't committed. I have nothing to hide.

"It is no secret that I was into partying in my teens and early 20's. I have not only smoked, but advocated for weed, I've experimented with drugs, my biggest song to date is about dancing on molly and snorting lines in the bathroom.

"I f**ked up and cheated in relationships when I was young.

"I lost a massive Walmart deal at 17 for ripping a bong.

"I got kicked off hotel Transylvania for buying Liam a penis cake for his birthday and licking it.

"I swung on a wrecking ball naked.

"There are probably more nudes of me on the internet than maybe any woman in history.

"But the truth is, once Liam & I reconciled,I meant it, & I was committed. There are NO secrets to uncover here. I've learned from every experience in my life. I'm not perfect, I don't want to be, it's boring. I've grown up in front of you, but the bottom line is, I HAVE GROWN UP.

"I can admit to a lot of things but I refuse to admit that my marriage ended because of cheating. Liam and I have been together for a decade. I've said it before & it remains true, I love Liam and always will.

"BUT at this point I had to make a healthy decision for myself to leave a previous life behind. I am the healthiest and happiest I have been in a long time. You can say I am a twerking, pot smoking , foul mouthed hillbilly but I am not a liar.

"I am proud to say, I am simply in a different place from where i was when I was a younger. (sic)"

Liam and Miley tied the knot in late December.