Authentic Edo-period original Japanese erotic art shunga woodblock print by Utagawa Kunisada (1786–1865), c.1827.  From his shunga series, Ehon Koi no Kaguya.
 
The shunga picture measures 26.7 × 20.8 cm.  Very good colors and impressions.  Condition is decent+/good, with some age-related wear and soiling and a small amount of wormage.  Album backing.  Please see and judge condition from the photos.
 
A rare and excellent original Kunisada shunga design depicting an amorously kinky couple abruptly interrupted by an intense-looking man, who appears determined to turn their private encounter into a threesome by penetrating the woman anally.
The wonderfully crowded composition, expressive faces, and unexpected intrusion give the scene a particularly provocative and almost theatrical quality.