a free loader
A free loader is someone who says 'I love you' but only shows up when there's snacks and drinks.
'I love you, babe!' he said, then took my last burger and left me with a napkin.
She said 'I'm here for you!' then took my chips and my beer and left me with a heartbreak.
He showed up at my door with a smile and a bag of pretzels. He left with my money and my soul.