"Fronting" is AE slang. It means to pretend like you are better than you actually are or that you have more than you actually do to impress people. People will "front" to make themselves look good in front of others. Here are a couple examples of "front":
1. You don't have to front around me, I know you don't really know what you're doing.
2. Jordan acted like his brother's new car was actually his. He was fronting to impress his date.