You know you're bulimic when

You choose food that tastes good coming back up rather than food that tastes good going down

Instead of calories eaten - calories burned, you calculate calories eaten - calories purged.

You stop doing your nails or using hand cream because you'll be stuffing your hand down your throat

There is no polish on the fingers you use to purge but all your other nails are perfect.

Whenever you touch someone they say 'your hands are freezing'

You know how to unclog drains in a number of ways

Your fiance reminds you that what you just said you wanted to eat means a binge ("I want a chocolate cake and a bowl of fried rice for dinner")

You tell people that you really don't like bread and then they ask where it all goes by the end of the week.

When you avoid food that's painful coming up, even if you love it.

You have a perfectly good drawer or cupboard or storage box that you can't use because it's your binge stash

When you know just how long you can be in the bathroom before your significant other asks if you are okay.

When you don't mind eating a bunch of food on the bus/train home because you are in binge mode

You can differentiate between laxative brands by their taste

When you don't even need to gag yourself anymore to throw up.

^That one^