You know I was in a relationship like this once. She was a bit chubby when we first started going out, but I didn't know if that was because she liked her meals or was just lazy. It didn't matter; if she wasn't a lazy little porker when we first started out going, by they time I had to move she had definitively crossed that line.
When she found out that I was into heavy girls, she let go and began eating more and more. Several meals on a date was not unusual. She'd do the most erotic things when she ate; talk about how fattening the food was, how much weight she was gaining, about how 'she could barely fit through (my) small patio door anymore' (that last on is a bit of an exaggeration, but by the end of our relationship I could have sworn I saw her almost getting stuck. A few more weeks of fattening and... wow.)
After a while we got into the Gretel scene. I enjoyed playing the witch immensely, but she loved being tied down and feed incredible amounts of food. I'd always be checking her meatiest parts and tell measuring her body. She always wore an outfit that she got a little before we started going out- she had a t-shirt that screamed 'feed me; I'm nice and fluffy!' and sweatpants that had 'juicy' scrawled around her bulging ass.
I'm out of time right now, but I'll finish this post up later.