An anal orgasm is intense and real, and the receiving partner may even ejaculate while completely flaccid.
Sex feels good for everyone, I don't know why this would be unbelievable to some. Anal sex is pleasurable and completely fine without the aid of any penile stimulation.
I have had 2 or 3 100% hands-off ejaculations in my lifetime from anal play or sex.
Anal sex feels good. Sometimes people cum. Anal sex is still great even if you don't happen to cum.
The End.
