Pete Wentz is forcing himself to stop swearing.

The Fall Out Boy rocker - who is married to Ashlee Simpson-Wentz - is growing increasingly conscious of his language around the couple's two-year-old son Bronx Mowgli after the youngster started mimicking his parents' phrases.

Pete said: "As a parent, I'm finally being able to get my mouth to behave itself as far as saying naughty words. He says everything!

"It's one of those things where he's so awesome, he just makes me smile. Even when he says bad words back, it's like, 'No way!' "

The 31-year-old rocker is astonished at how quickly he youngster has grown and is delighted to see him stepping out of babyhood.

He added to Us Weekly magazine: "He's becoming a human being, It's so crazy to watch something that was a baby become something so animated, so smart and so personable."

Pete recently spoke of how much he loves to watch Bronx around other children.

He said: "I've seen his empathy. If another kid falls down or if you burned yourself, he just hugs you or nods into you. Seeing empathy grow in him is awesome. He's a big, smart and nice boy."