'We think it's a boy!' Gossip Girl star Kaylee Defer expecting first child with Fitz And The Tantrums singer Michael Fitzpatrick

PUBLISHED: 23:56 EST, 8 May 2013 | UPDATED: 23:56 EST, 8 May 2013

Kaylee Defer is going from Gossip Girl to mother.

The 26-year-old actress confirmed to Us Weekly on Sunday that she was expecting her first child with 42-year-old boyfriend Michael Fitzpatrick.

Her bump was first shown to the public at the Mangria White Launch Party at the home of Adam Carolla in Malibu on Cinco de Mayo.

Here comes the baby bump: Gossip Girl star Kaylee DeFer, 26, announced to US Weekly she was expecting her first child with Fitz & the Tantrums lead singer Michael Fitzpatrick, 42, on Sunday

Defer explained that her pregnancy with Fitzpatrick was a surprise.

'We weren't planning on getting pregnant, so right now we're just enjoying being pregnant,' the actress said, explaining that the couple doesn't have any plans on getting married 'right now.'

At 20 weeks along, the mom-to-be says she is doing great.

'We think it's a boy. Well, the doctor is 95 percent sure it's a boy,' the Red State star explained. 'The baby was really shy that day, he was sleeping.'

Rising rock star: Fitzpatrick and his band Fitz and The Tantrums are rising stars in the Indie pop rock scene

Defer also reveals she has been cooking and baking a lot, saying she is constantly eating and snacking.

'I've been on a diet since I was 16. Not really, but I have had to watch my physique for the last 10 years of my life,' she said. 'It's my job, and now I'm just really guilt-free and enjoying being pregnant, sleeping a lot, eating a lot.'

Defer's boyfriend and father of her child Fitzpatrick is the lead singer of the dynamic soul pop group Fitz and The Tantrums, whose first record hit number one on the US Billboard heat charts in the summer of 2011 and is currently considered one of the hotter bands in the Indie pop rock scene.

Their sophomore album More Than Just A Dream was released on Tuesday, May 7.

Meanwhile, the television star says she is going to take a break from the acting side of the business for a while to venture into new creative outlets because of how much time she'll soon have on her hands.

'I've been wanting to take a break and now I can do the things I didn't have a chance to do before,' Defer says.