sex kitten vs sex bomb

sex kitten and sex bomb both are nouns.

Word	Noun	Adjective	Verb	Adverb
sex kitten	Yes	No	No	No
sex bomb	Yes	No	No	No

As nouns, sex kitten and sex bomb are synonyms defined as:

sex kitten and sex bomb: a young woman who is thought to have sex appeal

Other synonyms of sex kitten include sexpot.

sex kitten (noun)	sex bomb (noun)
a young woman who is thought to have sex appeal	a young woman who is thought to have sex appeal