23 year old Jacob Carter of Dryden was a baby sitter for a 3 year old boy and 1 year old girl.
Sheriff's investigators say he severely injured the boy by stomping on his stomach.
And they say he raped the girl.
Carter plead guilty to assault and sexual abuse charges.
The most serious is Predatory Sexual Assault Against a Child, and it carries a maximum of life in prison.
The Tompkins District Attorney asked for a sentence of 43 years to life.
The judge will decide the punishment when Carter is due back in court next month.