"It takes a lot of planning and organization which, if you know me, are two of my least awesome skills," she told People magazine. Still, she said they make an effort to see each other once a week.
The 27-year-old singer also admitted that like every other couple, they have their disagreements.
Apparently, Matthew has "ADD when it comes to the radio" and always wants to switch the station mid-song.
Hey, if song-switching is the biggest thing they're butting heads about, we'd say they're doing pretty well!
So, what song does Carly want to do a "full running time" jam to? She told the mag that she's really into Robin Thicke's "Blurred Lines" right now, but that Robyn, La Roux and Dragonette are also on her summer playlist.
What's on YOUR summer playlist? Tell us in the comments below.