MODEL PENAL CODE
In this Article, unless a different meaning plainly is required:
(1) the definitions given in Section 210.0 apply;
(2) "Sexual intercourse" includes intercourse per os or per anus, with some penetration however slight; emission is not required;
(3) "Deviate sexual intercourse" means sexual intercourse per os or per anus between human beings who are not husband and wife, and any form of sexual intercourse with an animal.