It is so sick and twisted and sadistic I truly have no words. You lose interest in the erotic aspects of it by just watching these weird pervy men shove their shafts and bulls (?) into tied up girls and try to get as many dongs in one girl as humanly possible.
The second half of this anime is just weird. Maybe you can get aroused by the couple from the first half, I get that, but a girl getting milked? Then these weird creatures just there? Don't watch it is the best advise that I can give regarding this one.
