Bethany Joy Lenz and Tyler Hynes are here for more Hallmark cheer.The duo co-star in Hallmark Channel's upcoming holiday film, which premieres the day after Thanksgiving, and only ET exclusively debuts a sneak peek.The story kicks off when a writer, Jamie (Hynes), convinces his his ex-girlfriend, Emily (Lenz), to pose as a faux couple for Christmas — a tried and true rom-com trope! As you can imagine, their pretend relationship takes an turn, for better or worse.In ET's exclusive clip, Jamie