Itsy-Bitsy

Once they could be studied, it was found that the little machines Irene had been infected with were keyed only to her DNA and inside anyone else they stopped replicating after a few generations.  Without pumping out the helium, those infected will inflate almost as big as Irene does, though after a while they will deflate when the nanites cease to funtion.  A pump will aid in deflation or control the inflation.  To operate, the nanites require a lot of energy which they get from consuming adipose so those who are repeatedly exposed tend to slim down very nicely.  

After the initial shock of being inflated like a helium balloon wore off, Irene's co-worker decided that she rather enjoyed the effect that the outgassed nanites had on her. Why not use them for a little fun?  So the following summer, she convinced Irene to go on a little vacation.  In their hotel room each morning, with her portable pump Irene would capture enough helium and nanites to dose her friend before heading out.

But without ankle weights or watches, they had to be careful and not stay out on the beach for too long...

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Irene is ©Throwaway261