Charlie Sheen went off on ex-wife Denise Richard's this past Father's Day in an epic Twitter rant, and now she's firing back.

In the now deleted tweets, Sheen referred to Richards as the "worst mom alive," along with many other disrespectful names, after she allegedly called him a "deadbeat dad" and sarcastically tweeted at him to have a "Happy Dad's Day" and a "great trip in Mexico." The two have been separated since 2006 after a rough divorce and custody battle. 

Sheen's rep, Jeff Billard, released a statement to PEOPLE on Monday in an attempt to help his client's case.

"Charlie was upset and chose to express his displeasure through his Twitter rant," Billard explained.

Richards had apparently declined Sheen's invitation to spend the day with their two daughters in Mexico.

Richards decided to fire back with a tweet directed at Billard instead of Sheen. 

"Jeff I think you had way too much to drink @jeffballardpr & lost your memory dude. Zip it," she wrote on Tuesday.

"Charlie hasn't seen his daughters in about two months," a source close to Richards told PEOPLE, defending the 44-year-old actress. "And he had no plans to be in town for Father's Day. There was no invite for Denise or the kids for them to join him in Mexico."

Billard is going to continue to defend his client and insists that the trip "had been planned for almost three weeks," according to E! News.

"Charlie invited Denise and their two girls," he continued. "But for whatever reason Denise chose not to go. For her to claim he only realized it was Father's Day on Sunday just isn't true."

Besides the tweet, Denise has declined to comment on the previously mentioned claims.

Billard and Sheen have also declined to comment on the entire incident, but Sheen's press agent has told E! News that he "was not willing to dignify her comment with a response."