"We just have been so happy. I can't even be upset with him, I can't stop smiling," Brittany Cartwright tells PEOPLE

Brittany Cartwright is over the moon about her engagement to Jax Taylor.

The Vanderpump Rules star, 29, opened up about their relationship to PEOPLE on Thursday and she can’t stop gushing about her fiancé.

“We just have been so happy. I can’t even be upset with him, I can’t stop smiling,” Cartwright said at the James Mae Clothing Launch in West Hollywood, California. James Mae is costar Kristen Doute’s clothing line.

Despite their love story having a lot of ups and downs — Taylor admitting to cheating and the couple splitting up briefly during the last season of Vanderpump Rules — Cartwright said they are back on track.

“We’re doing very good,” she added. “It’s just such a happy time right now.”

Cartwright also revealed she’s begun planning their nuptials with input from Taylor, 38, who she says “likes to have his opinion.”

“I’ll ask him for stuff and he’ll give his opinion,” she said. “He has good ideas too so I think it’ll be more fun to do it together. But I have the say, actually.”

National OOTD Day x Stassi Schroeder
Jax Taylor and Brittany Cartwright
| Credit: Lester Cohen/WireImage

“I’ve known where I wanted to get married since I was a little kid,” she continued. “I’ve talked about it on the show. Even in other seasons, I wanted to get married at the Kentucky Castle so I don’t think that’s a surprise. I have a date set and all that stuff, but I think I’m going to focus on the engagement party first.”

As for who will be her bridesmaids, Cartwright said Doute, who has slept with Taylor previously, “might” be in her wedding party.

“No one knows who’s a bridesmaid yet,” she said. “And I don’t want to say because my list is so long. I have so many really close friends, from home in Kentucky and here in L.A., so making my bridesmaid choices down to like eight [people] is going to be really hard for me because my list is at like 15 right now. So, that’s going to be the hardest thing.”

Cartwright and Taylor announced their engagement in early June. The Kentucky-born reality star showed off her stunning-cushion cut halo diamond engagement ring on Instagram.

“Omg omg!!!!!!!! We are ENGAGED! What a way to start our summer and season 7!! I am so happy, so in love, and so beyond excited for this next chapter of our lives! I can’t wait for all of you to see how he proposed! I am the happiest girl ever right now,” she wrote.

The couple celebrated their engagement at the low key beachside restaurant Neptune’s Net in Malibu, California.

And Taylor, how shared the same two photographs as his now wife-to-be, revealed their engagement will be on the next season of Vanderpump Rules.

RELATED VIDEO: Is ‘Vanderpump Rules’ Star Jax Taylor Getting Married?!

“She said yes!!! I can’t wait for y’all to see how this happened next season!!! I am marrying the woman of my dreams and I could not be happier!!” he captioned the images.

“My friend/brother @kylechandesign knocked it out of the park on this ring. I told him a few details but I trusted him and as you can see he came through above and beyond. When I decided to do this he was the only one I wanted to design Brittany’s ring and this is why.. flawless Kyle absolutely flawless. Also thank you Margaret owner of @Neptunesnet for allowing me to make this special day possible at one of our favorite spots to eat in Malibu.”

Bravo’s Andy Cohen congratulated Taylor in an Instagram comment, writing, “Mazel dude. Don’t f— it up.”