Babysitting a Curious Kid

It was my first baby sitting job. Jobs were hard to get in the real world when you are only 17, so I decided that baby sitting was about my only option. The parents had answered one of my fliers that I put up in the neighborhood. They wanted to go out and party or whatever, and so they needed me to watch their kid who was 13 for the night. Tony first appeared to be just be a shy boy, but then I judged that he was more hesitant then shy, like he just wanted to explode from his parents grasp. The parents left, wishing me luck and I started us out with a movie.
“Wait, before we start we have to get some soda!” Tony yelled.
“Hmm.. Ok, yeah, it is movie time right?” I went into the kitchen poured each of us a cup of orange soda. As I was about to finish filling up the second I heard Tony yell, “Popcorn too!” I accepted the request, grabbing a bag and putting it in the microwave. While that cooked I grabbed the soda and carried it into the kitchen. Half way there the microwave went beeping and Tony rushed off the couch and ran past me towards the kitchen. His sudden movement shocked me so much I tried to dodge him, dramatically, making myself go off balance, almost falling, and successfully spilling both drinks on my clothes.
“Hey what happened,” Tony asked, carrying the popcorn into the living room.
“Uh well you.. I spilt soda on myself.”
Tony laughed. “Oh.”
“I need to go get changed, where’s your guys’ washer and dryer?” I asked.
“Upstairs, on the right of my sister’s room.” Tony said, reminding me that he had a sister who was vacationing with their grandparents. I went upstairs, closed the laundry room’s door, stripped off my clothes and put them in the wash. I then realized I would have to find some replacement clothes.
I yelled down to Tony, “Would it be ok if I borrowed some clothes from your sister?”
“Yeah, ok.” I went into Tony’s sister’s room and looked through what clothes she had. Somehow I had gotten the impression that she was Tony’s older sister, but the clothes looked more appropriate for a 10 year old. I grabbed a light blue shirt and put it on. Looking myself down in a mirror I realized that the shirt only just covered the bottom of my boobs (they are 34C’s if you are wondering), and left my entire stomach exposed. I decided I had to move on, and tried a pair of panties on which were so small I wondered how I thought that was a possibility in the first place. The only thing I found that would fit were some gym shorts, since they had an elastic waist band. They were shorter then anything I would ever wear by choice. They only went down a quarter of an inch to cover my crotch, and when I turned around I saw that half my ass was sticking out.
“Well it’s just Tony and I here, so I don’t need to worry about what I look like.” I said softly to myself. I went downstairs to Tony and the movie, which he had already started. I sat down next to him onto the couch and started watching.
“What’s that?” Tony asked. At first I though he was asking about the movie, but then I noticed him pointing just above wear my shorts started.