"to my ex"
by stephanie harris

don't chew with your mouth open.
don't tell me we're as close
as sand and water on the beach.
now it's war: broken glass.
with gift after gift you set me up,
like ten pins in a game of bowling:
pin 1, a pager; pin 2, gold rings;
pin 3, a gold brooch for my mother;
pin 4, cds for my brothers; pin 5, expensive
dolls, paying for all my hair styles
and money any time i wanted it.
don't say you treated me like royalty.
i heard nothing but a cash register drawer.
our relationship, loneliness,
a ringing phone with no answer.

source: harris, stephanie. "to my ex." falling hard: 100 love poems by teenagers. ed. betsy franco. cambridge: candlewick press, 2008. print.

which word describes the tone of this poem best?

sentimental
bitter
nostalgic
optimistic