Can we get something frackin' straight here (this is a response to konchog highlighting certain points in the tantra quote and to "accusations" by other posters) I HAVE NEVER SAID THAT SEX IS SOMETHING THAT IS WRONG OR TO BE AVOIDED!
Are we clear now?
As to this:
Heterosexual yogis have it so easy ....
One of the female forms pictured above is not a genetic (XX) woman. Secondly it's not so easy coz many heterosexual yogis do not respect women and thus will gain no Success as outlined by Vajrayogini in the Tantra AND they do not satisfy one of the other important criteria:
...instantly to those who desire the welfare of all beings
And finally, if you (or any of the other aspiring yogis in this thread) bother reading the whole of the Tantra, to which I provided a link, the practices necessary to achieve realisation through this Tantra are nowhere near as simple as "shagging" a "fit bird". I recommend some of the aspiring yogis here to go and read the entire practice, I imagine that the majority of them will quickly abandon any thoughts and wishes of appeasing Vajrayogini or any other dakini for that matter!
PS This clause here may also be of interest:
Mother, sister, wife, maternal aunt, niece, paternal aunt, mother in law, and all other caste relations
As it basically says that all these female forms should also be subjects of sexual union by the yogi!