It's war!

Kevin Federline, 37, took to Twitter last night to call out Beyoncé's changing looks after a popular sports blog tweeted about Bey's ample cleavage, prompting the ex-husband of Britney Spears to share his thoughts about her possible Botox and plastic surgery.

RELATED: Did Beyoncé Have Plastic Surgery After Giving Birth to Blue Ivy?

kevin federline and beyonce

Plenty of people slammed K-Fed for his comments, but he wasn't finished bashing the 34-year-old Grammy winner.

Beyoncé hasn't responded to the attack, but we bet she's not happy!

See more celebrities who've been scrutinized for going under the knife