EXCLUSIVE: Heather Thomson reveals why she's not returning to 'The Real Housewives of New York'

Bad news for Heather Thomson fans.

The 45-year-old reality star told ET on Tuesday that she's not returning for the next season of Real Housewives of New York. Thomson said that filming the hit Bravo show was taking away from time she could be spending with her family, and also running her business. Thomson has her own fashion brand, Yummie by Heather Thomson.

"The reality of it that I just can't do it anymore," she admitted to ET. "I have to focus on the things that are really, really important in my life and that's my family and my business. While I'm filming the show I also am running a multi-million dollar business, and it takes away a lot of my time from the company."

PHOTOS: See all the former 'Real Housewives'

WATCH: Heather Thomson Tells All

Thomson signed onto the reality show three years ago, and said that her third year felt like "the end."

"My third year I kind of figured out where I was with the women," she shared. "There was a beginning, middle and end for everything, and for me, that was the end."

"The opportunity, the experience -- it was all amazing while it lasted," she added. "But, again ... the third time was the charm for me."

Thomson has no regrets about her time on the show, sharing that it's made her "wiser."

"They don't match you with normal people you'd gravitate toward -- that's the genius of the casting," she revealed. "They put you in a situation of people you wouldn't normally be with ... that is interesting to see you react and interact with someone you wouldn't normally hang out with. ... Ramona [Singer] is not someone that I think if we met socially, either of us would gravitate towards one another ... we overcame our differences."

That being said, Thomson also commented that she's keeping the "door open" for Bravo in terms of making any future cameos or appearances.

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Check out the video below to see Thomson's fellow RHONY star all smiles out with Tori Spelling last month, on the same days news broke that her husband, Josh Taekman, had an active Ashley Madison account.