Green’s Dictionary of Slang

to indulge in foreplay.

1873		Sl. Dict. 162: Firkytoodle to cuddle or fondle.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1896		Farmer Vocabula Amatoria (1966) 13: Amuser 1. To excite the senses; ‘to firkytoodle’.