Gwyneth Paltrow better watch out! Her Coldplay frontman hubby, Chris Martin, was spied making out with actress - and Cohasset homey - Kate Bosworth at a recent U2 concert! “I couldn’t believe my eyes - there was Chris Martin totally making out with Kate in front of other people,” a source told Star magazine. However, reps for Gwyneth, Chris and Kate have all denied the tale. Martin’s rep called the story “entirely untrue,” Us Weekly magazine reports.