Lindsay Lohan sure knows how to hold onto a grudge. The Mean Girls star hasn’t forgotten how former BF Calum Best dumped her during her Summer 2007 stint in rehab. And that’s precisely why Lindsay turned her nose up at an opportunity to appear on Calum’s MTV One (UK) reality show, Totally Calum Best: The Best Is Yet To Come. Calum blew up Lindsay’s cell to no avail in hopes of getting the actress to attend a taping for the show in Hollywood last week.

“It was clear Lindsay had no intention of attending Calum’s tacky pool party,” an insider laughs to the Daily Mail. “She has heard about the MTV series but she has no intention of going near it — and she hasn’t replied to any of his messages.”

“She feels he used her once before and she isn’t about to fall for it again.”