Brian Austin Green has vowed to "shut up and sit back" after lashing out at Machine Gun Kelly. The Beverly Hills, 90210 star recently took to social media to slam the rapper's behaviour following his split from Megan Fox,

The "Beverly Hills, 90210" actor said his recent out-of-character diss of his ex's ex are the last you'll hear from him on the topic.

Brian Austin Green's marriage to Megan Fox might not have made it, but he will always have her back. The Beverly Hills, 90210actor explained why he took the time to publicly call out Fox's ex Machine Gun Kelly — whom she's currently expecting a baby with — via his Instagram Story during a recent appearance at the Hollywood Virgin Los Angeles