By Lucretia Munro Love Island viewers are set to witness an explosive showdown between Liberty Poole and Mitch Taylor after finding out he’s been pursuing Demi Jones behind her back. Liberty, 24, has been in a couple with Mitch, nicknamed Messy Mitch, but has been at a crossroads after noticing the hunk has not been putting in any effort – and now she knows why. During a conversation with pal Demi Jones, Liberty finds out that he pulled Demi to one side to tell her that he counts her as his “number one” girl. After being told the bombshell news, in scenes that will air later tonight, Liberty e…