the body is in motion, and is thrown into all postures, frequently into very indecent ones

In his book “TRAVELS THROUGH PORTUGAL AND SPAIN, In 1772 AND 1773” RICHARD TWISS, F. R. S. (1747-1821) describes the Fandango being danced an inn in Mafra in Portugal,
“The dance itself is for two persons, and much like the Dutch plugge dansen. I imagine the Dutch, by having been so long under the Spanish dominion, have retained this dance, as well; as many other customs. For instance, the veils ; which are large square pieces of black silk, that the women, when walking, throw over their heads, and keep nearly closed over their faces. The Spanish name is velo the Dutch call it saly. The custom of smoking tobacco the inhabitants of the Netherlands have probably also derived from the Spaniards. The pronunciation of the two languages in the harsh and guttural G, is exactly the fame.

But to return to the fandango. Every part of the body is in motion, and is thrown into all postures, frequently into very indecent ones.    Stamping the time with the feet, and playing all the while with the castanets which are a kind of small shells of ivory, or hard wood, of which two are rattled together in each hand.    When they have not these instruments, they snap with their fingers and thumbs.    The dancers approach, turn, retire, and approach again; the man with his hat on.    I afterwards saw this dance to greater perfection on the stage, to the music of the whole orchestra.   It seems the tune is always identically the fame. When these dancers were tired, and in a profuse sweat with the violence of the exercise, their place was immediately supplied by another couple, as the room was  by this time filled   with most of the decent people of the village, who having danced in their turns, I disregarded the musician,  and passed the remainder of the evening in playing a rubber at whist with my landlady, her husband, and her sister.”

In his book The Code of Terpsicore in 1830 Carlo Blasis Italian dancer, choreographer and dance theoretician

"A young girl, of bold character, places in her hand two castaguettes of sonorous wood. By the aid of her fingers she produces a clattering noise, and to that she keeps time with graceful motions of her feet. The young man holds a tambourine (or a tambour de basque, which, however, is now out of use), this he strikes with little bells, seemingly, as it were, to invite his companion to accompany him in gesticulation. While dancing, both alternately playing the same air, both keep time to its measure.

Every description of lascivious motion, every gesture that is offensive to modesty, and whatever can corrupt innocence and honesty is represented by these dancers, to the life. Alternately do they salute, exchanging amorous looks; they give their hips a certain immodest motion, then they meet and press their breasts together; their eyes appear half closed, and they seem, even while dancing, to be approaching the final embrace."

Given these descriptions it is not surprising to discover that in Georgian Bath performances of the Fandango seem to have been largely confined to the circus and the theatre.

Bath Chronicle 1822

The Giroux sisters who performed on the 3rd February were from a family of the theatrical dancers but had settled in Bath and Bristol where they ran successful dance academies.