Pete Wentz is set to become a father for the second time.

The Fall Out Boy bass player and his model girlfriend Meagan Camper announced today she is pregnant, with a photo on Instagram of them kissing and Pete, 34, touching her stomach. Beside the photo, they wrote, "We're super excited to announce we're expecting a baby!"

Pete - who has five-year-old son Bronx Mowgli with his ex-wife, Ashlee Simpson - and Meagan have been hoping to start a family for a while. "They've been planning on this for a while. And they're really excited for Bronx to have a new little buddy. Meagan is a big sister and has a great relationship with Bronx. She's naturally maternal so this is perfect," a source said.

Pete and Meagan started dating in September 2011 and he recently said they are also hoping to get married soon. "We talk about [marriage] a lot. I feel really lucky. It's really interesting when you're in a relationship with somebody who's truly my best friend. I talk to her about everything. She will tell me when I'm being not so insane, and sometimes she's like, 'You're being a little bit insane.' So, it's very helpful," he said.