The dog and the marshmellow

My mother gave Lia a large marshmellow the other day:

Lia: *bites down on marshmellow*
Marshmellow: *gives and pops back to normal size again*
Lia: *spits out marshmellow, looks at it, then grabs it and CHEWS it*
Marshmellow: *gives and pops back to normal size again*
Lia: *spits out marshmellow, looks at it veeeeeeery suspiciously and then swallows it in one big gulp.*
Marshmellow: *is eaten*