This is probably an extension of facial coverings/masks in general that are used by some fetishists. I don't understand the appeal of the whole rubber/plastic/masks area, so I can't comment as to what its about. I suppose you have to be into these things to understand it.
That's awesome I know the feeling I love watching porn like that! Any hot fetish sex gets me off gets me hard instantly. And the load that comes after that is
I've just been watching CD's wanking, cumming and getting fucked hard, I love it and am rock hard myself. Time to go and stroke one out I think and there will be plenty of cum too.