This term was originally from a line in one of the 20th centuries most admired poems, T.S. Elliot's 'The Love Song of J. Alfred Prufrock' in which the poets asks a number of rhetorical questions in which he wonders about the meaning of life and questions his own inability to overcome his indecisions. In this poem the chorus line is: 'In the room the women come and go Talking of Michelangelo.' Among the many questions he poses to himself is 'Shall I part my hair behind? Do I dare to eat a peach? I believe you will find this is the genesis of the Eat a Peach meaning.

someone who is sexy beyond mean

Slang term for cunnilingus, or, the oral stimulation of the female genetalia.

Or more simply, eating a girl out.

To eat ass all day

When a lesbian wishes to put an end useless conversation with authority, or with a nasty remark. Similar to the phrase "Eat a dick"

To eat ass all day!