"He's the perfect partner for me and I feel like we evolve," the Criminal Minds star, 43, tells PEOPLE of her engagement to actor/writer Keith Hanson. "When you're so into somebody and you get to just mush up next to them – that's the best part of it."
The actress' future hubby only popped the question a couple of weeks ago surrounded by family and friends, but she's already comparing wedding planning to her everyday task of producing plays (it takes about six weeks for her to do so), and she's questioning, "how hard can it be?"
"He's more particular than I am, which is going to be fine, but he has many more requirements than I do," Vangsness says of her hopeless romantic fiancé. "It might take a little while longer, but it's a quality problem."
Vangsness says that she has started planning some aspects of her fairytale day, but rather than narrowing down her ideas, she says she's going to try to incorporate everything!
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"The only thing I know I think I want is that I want to spray paint dinosaurs gold and use them as table markers, so that you could be like, 'you're at stegosaurus,' but I might try to merge all my favorite things, so it would be like a Harry Potter/Chronicles of Narnia/dinosaurs/Doctor Who wedding," she jokes. "I asked [Keith] what he thought about getting a horse and putting a horn on it and everyone could take pictures with a unicorn."
And with a very unique wedding comes an even more unique dress.
"I want a plaid dress that's so cool I could wear it to something else," says Vangsness. "I want to wear my wedding dress and then when I get nominated for my first big award I want to wear that, so people could be like, 'she wore her wedding dress!'"
It's clear that Vangsness could not be more excited about her future, but there is one thing she wants to clear up for her fans, who may not know the circumstances surrounding the end her previous engagement to Melanie Goldstein, to whom she became engaged in February 2009 after two and a half years of dating.
"I was so in love with her, but in terms of life growth, what we were both doing separately was just pulling us apart, not sexually, but in all other ways in terms of what your dreams are and what you want to go after and all that," says Vangsness, who will be attending the Film Noir Festival in Paris later this month to promote her new film Kill Me Deadly. "Growth takes people in weird paths and all of the sudden our relationship wasn't able to sustain what I wanted to do and in terms of what she wanted to do, so we kind of had to call it."
Though she has been engaged to both a man and a woman, Vangsness says she doesn't identify as bisexual.
"I guess I never understood the term of being bisexual because once I let myself come out ten or 12 years ago, I was like, 'Oh, okay I'm gay,' and I was perfectly okay with that, but then I was like, 'Wait, nothing changed in me,' " says Vangsness. "I don't feel any different."
She continues, "The person I'm with, I can tell you, is very, very special and the right person for me. I was not expecting it to be a guy, but everyone has his or her own intricate stories. If I were straight, I would say I was, but I don't totally understand it myself. I don't want to have an answer to something that I don't really have an answer to."