Could be counting either orgasms or rapings. Depends on your imagination as there is no one depicted behind them. It's pretty good in that respect. Only thing is that nothing appears to be supporting those devices. By the way it's drawn, they appear to just be hovering in mid air.
There some semen on the ground at their feet. Seems like rapings, but as Astral said, seems like an awful willing position... well trained sex slaves perhaps?
I don't think that's male cum. Ero artists have a big tendency to draw that so that it stands out. If it were white or off-white, I'd have agreed, but it's transparent on the girls' legs.