Kevin Federline doesn’t waste time. On December 22, less than a month after ex Britney Spears partied with Lindsay Lohan, the aspiring rapper, 28, texted the actress, 20, suggesting, “We should hang out.”

But, as reported in the new issue of Us Weekly, the invite went over about as well as K-Fed’s debut album. “She was totally grossed out,” a Lohan pal tells Us.

Says another, “She thought it was hilarious.”

However, Federline didn’t appreciate Lohan’s “Why would I hang out with you?” reply. He fired back, calling her a “firecrotch.”

Says the source, “She couldn’t believe he was so pathetic. She doesn’t want him using her to make Britney jealous.” Both in Miami to ring in 2007, Lohan avoided Federline at Mansion nightclub on New Year’s Eve.

Crazy kids with their crazy illusions!