mosquito bites on her nipples

Tonight, as she was getting ready for bed, Sophie put on a bikini top.  Here's how the conversation went:

Sophie: Is it okay if I wear this to bed?

Me: Underneath your nightgown?

Sophie: Yeah. Under my nightgown.

Me: Why are you wearing it?

Sophie: (pulls down the front of the bikini top and fingers her nipples) I need it so that the mosquitos won't bite these.

Me: Your nipples?

Sophie: Yeah.  My nipples. Is it okay if I wear it?

Me: Sure. Now go put on a nightgown.

Then we read the Lorax and she fell asleep.

Just before that conversation, I almost killed her.  She had pooped in her pullup and wanted me to clean it up.  The policy around here, per the poop doctor, is that she is supposed to clean it up herself.  She knows that and yet any time she has to do it before bedtime, she throws a fit, complete with tears and her special form of of ranting to herself. She did it last night too, and KC just ignored her.  But tonight it pushed me over the edge and I chewed her a new one.  I didn't raise my voice, but I told her to "get in the bathroom, clean up, and don't say one more word about it" in my most serious, pissed off mom voice. She looked at me, walked into the bathroom and the next thing I knew she was all cleaned up, ready for bed, wearing a bikini top and singing to herself.

It was at that moment I realized that she is totally yanking my chain. The poop doctor keeps saying, "don't comment on it," "make it a non-issue," "leave the room if you have to," but there is a growing part of me that thinks this method won't work with Sophie. It is possible that of the hundreds of children she's seen, mine is different.  I'm contemplating just laying down the law, and seeing if Sophie magically gets it together. This "turn the other cheek" crap isn't working.