It wasn't weird to be in love with a mannequin, was it?
Sure, Alex had to make up an entire fake history for Manny (that involved amnesia) just so people wouldn't get suspicious when he said he'd lived in a store window his entire life.
But once she'd reanimated him – and put all his limbs back in the right places – he was the same as any other boy. A living, breathing boy with a heartbeat she could hear when she rested her head on his chest.
And after all, he loved her. Who cared if he'd only just discovered emotions?