The 31-year-old "Pieces of Me" hitmaker says she finds the way Bronx enjoys music very cute, reported People magazine.
"He's so into music. He loves to dance around and he writes little songs. They're good! It's so cute," she says of her son with ex-husband Pete Wentz.
Simpson and her husband Evan Ross, are also planning to present him a guitar on his seventh birthday next month.
"We're going to have to get Bronx a Guitar Hero Live," Ross said.