Green’s Dictionary of Slang

tale of two cities n.

[rhy. sl. = titties (titty n. (1))]

the female breasts.

[UK]J. Franklyn Dict. of Rhy. Sl.
[US]Maledicta II:1+2 (Summer/Winter) 118: He gives us several terms for tits/titties (Bristol Cities, cat and kitties, Tale of Two Cities).