Opinion Sponge

A person who soaks in the opinions of others when they are in their company. They adapt to these opinions very quickly and, like a sponge, emit the same content they have soaked in when questioned (or rinsed).

When in the company of vegetarians: ikr I NEVER eat meat. think of the poor animals!

When in company of normal people (meat eaters) : Urgh I'm so fat because I eat so many Big Macs, i just can't get enough of them

Everyone else: She is such an opinion sponge!