Within the guidelines of halacha as presented by chazal and early rabbinic authorities, fellatio is classified as ביאה דרך איברים Penetration by way of the limbs) or מעשה חידודים בעלמא (General acts of sharpening). Peripheral Halachic discussion of the topic revolves upon whether or not a husband may engage in varying sexually-gratifying acts with his wife - of which include fellatio - performed up to and including a complete extra-vaginal ejaculation.