That joke about the young bull who tells the old bull, ‘Hey, Dad, see all those cows — let’s run and get one of them,’ and the old one replies, ‘Let’s walk and we can have the lot,’ is of course far too politically incorrect to tell these days. But it did creep into my mind last week watching Birmingham Royal Ballet’s double bill of Frederick Ashton’s masterworks, The Dream and A Month in the Country.

He’s the old bull, and after the Duracell rogering in Christopher Wheeldon’s Strapless the other week, the serene, sly, ceaselessly sensuous way Ashton seduces you in those ballets, with choreography that never stoops to representing sex itself, comes like a caress after a grunt.

I say ‘stoops to representing sex’ not because I think doing so is low — Kenneth MacMillan was a genius at it, choreographing some viscerally exciting sex scenes, as well as some scarily abusive ones (see the imminent The Invitation at Covent Garden in May) — but because, as someone else said, dance is the vertical expression of the horizontal, and Wheeldon was far, far too horizontal. Using choreography to spell out full sex between two people wearing tights, breeches, leotards and jockstraps is somewhat laughable. Split and splayed legs, bump and grind, changing position every ten seconds. You can’t empathise with it.

Smart choreographers such as Ashton and MacMillan make the moves represent sexy feelings, not actions, the arc of desire, mining the foreplay of frisson and hopefulness, exploiting the rising ardour in increasingly risky moves, a superbly climactic orgasmic high (for both, happily, or one, tragically), then descending in tenderness or hatred. Then the audience’s juices or tears will flow.

The Dream, Ashton’s Shakespearean hour to Mendelssohn’s magical music, is soaked in sex. The fairy monarchs Oberon and Titania play very risky games with each other, including bestiality, racism, child abuse and cruelty to human beings, all as foreplay, wrapped up in that fantastically erotic reconciliation pas de deux. To picture sex would be banal. Here instead are couple-moves so extraordinarily descriptive of a proud dominant man being beguiled by his flirt of a wife, who wriggles deliciously and uninhibitedly out of every position he tries to control her in, that you are sucked into their amoral love affair. When they join arms and each balance on one leg, the symmetry of this breathtaking pose says something glorious about the equal halves of love.

I felt this exultation in the performance of William Bracewell and Jenna Roberts, even if the noble Bracewell isn’t as confident in the typhoon speed of the legwork as great Oberons are. But their erotic game-playing turned Birmingham Hippodrome’s stage into a fantasy forest.

The sex in A Month in the Country is never fulfilled but it burns like hell. Set opulently in Julia Trevelyan Oman’s peerless Russian country mansion, with Chopin on the piano, things start in idleness, as mistress of the household Natalia Petrovna, mildly bored of her daffy, keys-forgetting husband and the poodle eyes of bachelor neighbour Rakitin, awaits the children’s new tutor.

As soon as their eyes meet, God, how she wants to sleep with him, Ashton shows you. How easily, meanwhile, he flirts with the maid and Petrovna’s teenage ward Vera. Sex is clearly potentially only a door away there. The secret, furtive duet that he and Petrovna manage to snatch is her fantasy, very virginal in her demands compared with Titania’s, a woman’s unlived, unliveable life expressed so tearfully that young Beliaev simply accedes to her emotions. Two such different women, two such different men, and such enrapturing experiences of vicarious sexual love. No batteries required.

Delia Mathews was an exceptional Petrovna, with a revealing face; Karla Doorbar was even better as young Vera, dashing like a hummingbird, coming to orgasm simply from excitement. Lovely playing by the Royal Ballet Sinfonia and Jonathan Higgins of Ashton and John Lanchbery’s brilliant Chopin arrangement.

As I said in the Wheeldon context the other week, people in the independent dance-theatre sector nowadays are delivering human emotion and gut excitement rather well. You feel anticipation anyway just hearing that someone is doing Homer’s The Odyssey as a dance production in the matchbox-sized Wilton’s Music Hall. I loved Mark Bruce’s previous creation, Dracula, and this one has a similarly fabulous set (Phil Eddolls) and lighting (Guy Hoare), and a hearty slash-and-burn attitude to both music (heavy metal meets Mozart Requiem) and Homer’s epic scenario. If you know the story, you might well be amused.

Yet I was disappointed that the choreography can’t match up to Bruce’s admirable ambition, since choreography is the language of Odysseus and Penelope’s different experiences of lostness. The intense staring eyes of Christopher Tandy and Hannah Kidd can’t disguise that their parts are severely underwritten, and much is also lost by the forced withdrawal of Jonathan Goddard, the originally intended deity playing vicious games with the humans.

Much the best time in this loud, gory, slightly camp experience is had by the Rocky Horror Show-style Immortal goddess Eleanor Duval, a divine vamp, and the stagehands who designed the blood-spurting props.