Every. Single. Night. We put her down, she's quiet for 20 minutes, and then we go in and she's completely naked, nappy flung across the room, and it's either a wet bed or... worse.
We've tried: onesies (she's worked out the poppers), putting them on backwards, a sleeping bag (unzips it). I'm washing a cot sheet every morning. She thinks it's hilarious.
