The former One Tree Hill star began dating Gilbert late last year (12) and they made their red carpet debut at the CMA Awards in November (12).
Now Kramer reveals they have put their relationship to the test by splashing out on a new love nest in Nashville, Tennessee.
She jokes to CMT Radio Live, "I actually bought the house, and he is living with me, yes. He's paying his little monthly rent."
The beauty insists the new living situation is going well, but she and Gilbert argue over closet space, adding, "It's hilarious. You walk in and to the right are all my colours and sparkly clothes and then Brantley has the left side of the closet and it's all black. Actually, I take that back. I bought him four red shirts, and they stick out like a sore thumb."
But Kramer insists she couldn't be happier: "I am really happy. (Brantley) is so wonderful, I cannot stop smiling around him. He surprises me with gifts 'just because.'"
The 29 year old was previously married to Christina Applegate's ex Johnathon Schaech, but they split a month after their wedding in 2010.