Rachel Bilson will only date someone if they are "all about her kid".

Rachel Bilson

Rachel Bilson

The former 'The O.C.' star has four-year-old daughter Briar with her ex-boyfriend Hayden Christensen and she has opened up about the difficulties she has dating as a single mom.

Discussing the worst dates she has had on 'Bachelor' alumni Nick Viall's The Viall Files podcast, she recalled: "I was talking to these guys a few months back, anytime I would bring my daughter up, they would never pursue the question or ask more about her.

"It was a red flag because anyone that you're going to get involved with, if you have a kid, they have to be all about the kid."

The 37-year-old star says she is always up front about being a mother with potential suitors.

She continued: "I always put it out there.

"She's my world and I talk about her all the time. How f***ed up would it be if I hid that? ... If you're going to pursue something with someone, they have to be interested in the kid or be willing to be around the kid."

And the 'Lovestruck' actress admitted she won't let her daughter meet any of her dates unless it's "serious".

She said: "She has not met anyone as of yet and it would have to be someone I know I'm going to be with.

"It would have to be a very serious relationship."

The 'Jumper' star - who previously dated her 'The O.C. co-star Adam Brody for three years between 2003 and 2006 - also opened up about keeping her little girl out of the limelight until she is old enough to decide if she wants to be in the public eye.

She said: "Everybody has a different idea of what they want to do with their kids and what not.

"They don't choose to be in the limelight, you know, themselves.

"When they're old enough and they want to pursue it and that's what they do then that's fine.

"But it's not like I want to promote my kid or put her out there."

However, it's not been easy.

She said: "I saw a picture the other day of my daughter somewhere and she's looking at the camera smiling because she has no idea.

"She thinks someone is just taking her picture ... It crushed me."