Why won't my 6week old kitten eat?

My boyfriend bought me a boy kitten from a pet store yesterday for Valentine's Day but he won't eat his food. I bought him Purina Kitten Chow and he's only eaten one or two bites of it. It seems like he just doesn't want to chew it. He's been drinking tons of water and has gone to the bathroom three times in the litter box so I don't know why he won't eat. Help!