In the interest of providing useful bibliographies . . . here's a list of references for words in use in the Regency Period for explicit behavior.
You'll note a good many of these works are fifty or sixty years after the Regency. If you find a promising word or phrase in some later reference, you'll need to go back and check it.
Educated folks would have also read French and Latin erotic classics. The Satryicon was available in German in the Regency era, for instance.
The Slang Dictionary. Hotten. 1859. Here.
Grose's Classical Ditionary of the Vulgar Tongue. Pierce Egan. 1823. here.
A Physical View of Man and Woman in a State of Marriage. de Lignac. 1798. Here.
Dictionary of Slang, Jargon and Cant. Barrere and Leland. 1889 Here.
The Works of Francis Rabelais. Here .
Slang. Badcock. 1823. Here.
A Dictionary of Slang, Jargon and Cant. Leland. 1890. Here.
Philosophy in the Bedroom and 120 Days of Sodom. De Sade Here.
The Lustful Turk. John Benjamin Brookes. 1828. Here.
A Night in a Moorish Harem. Anon. 1896. Here.
Aphrodisiacs and Anti-aphrodisiacs. John Davenport. 1869. here.
Autobiography of a Flea. Anon. 1901. Here.
My Secret Life. Anon. 1888. Here.
The Kama Sutra of Vatsayayana. Richard Burton. Here.
Liber Amoris or the New Pygmalian. William Hazlitt. 1823.here.
The London Bawd. Anon. 1705. here.
Memoirs of a Young Rakehell. Guillaume Appollinaire. 1907.Here.
The New Ladies Tickler. Anon. 1866. Here.
The Romance of Lust Anon. 1873. Here.
The Three Chums. Ridley. 1882. Here.
The Way of a Man with a Maid. Anon.
I don't know where this is free online, but it can be downloaded for a small fee several places.
I'd recommend picking up C18 and C19 erotic wordage from the period literature rather than period dictionaries.
The couple few C18 slang 'dictionaries' are irreplaceable for confirmation of earliest date.
They're less reliable for showing usage.
What it is -- these early dictionaries were intended for entertainment rather than scholarly reference. They conflate clever one-offs, (a good many created by the author, I suspect,) with true slang.
So it's cute to call a coachman a 'Knight of the Whip'? as per Grosse, but it sounds like literary affectation, not what one character could say to another. And calling a whore an 'Athanasian wench'??
Not so much.
The slang, 'blowen' -- meaning a woman -- gets 630 hits on googlebooks for the 1700-1830 time period. 'Athanasian wench' appears only in Grosse.
So I'd pull erotic usage out of the literature and then check the dctionaries for confirmation. Or googlebook search.
I am just in love with googlebook search.