The second guy kneels over her head and enjoys a blowjob in the position.
But there are other reasons, too.
Everyone has heard about the multiple orgasms of a woman.
Men need time to recover from ejaculation, and a threesome is a perfect option for this.
Be careful with this though.
The Voyeur lets you ease yourself into proceedings in style … Technique: The man and first woman start to have sex in any position of their choosing.
There is ample evidence for the plasticity of female sexuality including orientation and far less evidence in men.
No surprise to anyone, but those encounters are undoubtedly queer.