Kristin Cavallari. [Photo/Agencies]

Kristin Cavallari is having a boy.

The 25-year-old star and her partner Jay Cutler are expecting their first baby and although they haven't divulged the sex, Jay's Chicago Bears teammate accidently broke the news today (02.05.12).

Speaking on 'The Boers and Bernstein Show' radio show, Earl Bennett said: "New toys, a baby on the way--he's having a boy--and, you know, I'm excited for Jay. It's a great time."

Afterwards, the show's host declared: "Jay's having a boy. I don't think anybody knew that before then."

Kristin has previously revealed she couldn't wait to find out if she was having a boy or girl, but would not mind what it turns out to be.

She said: "I do want to find out what I'm having, I couldn't wait. I don't care what the sex is. A little girl would be fun, to put little tutus on her, but a boy would be great, so I don't care."

The former 'Hills' beauty has also been getting advice from her mother and some girlfriends about how to deal with pregnancy and birth, but believes it is pointless doing too much research because ''every baby is different''.

She added: "I've read a couple of pregnancy books and now I'm on to what to expect the first year which I actually think is more important because once the baby comes it's like, 'Now what?' But my mother has been a huge help and I've had some girlfriends who have been great. Every baby is different so you can only do so much research."

Kristin is believed to be in her second trimester but has not revealed her due date.