"It's a very strange feeling being paired with [someone new] this week. We get along like a house on fire," Murgatroyd wrote in her People blog.
Monday night's Dancing with the Stars broadcast will feature the season's special "Switch-Up" twist in which the professional and celebrity pairings will be changed based on whom America would like to see dance together in the competition. The eighteenth edition's original pairings will resume next week.
"[My new partner] is so funny and so sweet, but I'm still obviously in contact with James. We've been texting and calling each other just to check up and see how each other's dances are going. It's just weird because I'm thinking about camera blocking and how I'm not going to be with James," Murgatroyd explained.
The 27-year-old pro dancer also touched upon Maslow's "most memorable year" story from last week's performance show. Maslow, 23, had revealed he was overweight and bullied as a kid but eventually transformed his body and became confident enough to star on Nickelodeon and sing for Big Time Rush.
"I'm glad he went with the bullying angle... because we had another option to tell the story of his life on the road with Big Time Rush. We both sort of felt that wasn't enough to tell. We needed to show the real James who has struggled with his weight -- not just the James people already know by watching the show," Murgatroyd wrote.
"I think people assume that those who are so heavily in the spotlight have looked a certain way their entire life and that it's been easy. James is so dedicated to health and fitness. He really takes it seriously. When everyone else is grabbing crappy snacks and fatty stuff to eat, he always opts for the healthier snack."
Murgatroyd also admitted Maslow's healthy eating habits are rubbing off on her.
"It's great for me, too, because sometimes I get in the habit of eating whatever is in the dance studio," she explained.
"There are granola bars and packs of chips, which are okay once in a while, but he is like, 'Peta, no, let's order in food.' So, we order salads and vegetables and stuff like that. He's just on this health kick and he looks amazing. He's a sexy guy."