Green’s Dictionary of Slang

1. a scolding, a telling of; usu. matrimonial.

c.1850		Mrs. Cuddle’s Bed-Room Lectures 10–15 6: When Cuddle he came home at night, / To face his sweet tormenting wife, / Tongue pie at him she’d sweetly pour, / At the rate of sixty miles or more.
1878		Star (Guernsey) 9 Apr. 2/7: Members, as a rule, are partial to ‘tongue pie.’ They like to tread upon each other’s corns.
1899		York Herald 21 Oct. 16/3: ‘Tongue Pie’. Doctor: ‘I’m afraid you wife has a disease of the jaw, Mr Nagg.’ Mr Nagg: ‘I dare say; I know “jaw” is a disease with her’.
1901		Sydney Sportsman (Surry Hills, NSW) 16 Oct. 2/7: I hears the gel a -cryin’ / And the mother, pipin’ hot / Givin’ her tongue-pie.
1907		Sun. Times (Perth) 21 Apr. 1/1: His innuendoes to mere school girls got him a repast of tongue pie. [...] He is also a trifle too free with his comments on calves.
1923		J. Manchon Le Slang.
1928		Nott. Eve. Post 10 Dec. 1/5: If there is one thing I can’t stand it is tongue pie.
1931		Eve. teleg. (Dundee) 2 Jan. 2/3: Defendant at West Ham to the Magistrate— If you are a married man, sir, you know what tongue pie [is]!
1968		Boston Globe (MA) 5 Mar. 24/7: Tongue pie ‘a severe scolding.
1972		Hartford Courant (CT) 12 Nov. 4F/4: Gloss. of Cockney Eng. [...] A tongue pie is a severe scolding.

2. cunnilingus.

1989

J. Morton Lowspeak.