Used bra fetish for masturbation.

I have always had a thing about breasts, ever since I was young. My earliest masturbation activities involved looking at the lingerie section of clothing catalogues.
As I got older, occasionally I would have the chance to get access to underwear drawers and discovered that I absolutely love the feeling of the material against my penis when I masturbate.
The idea that the fabric has been in contact with breasts and nipples drives me crazy.
I used to fantasize about getting caught by the owner and what might happen.
Recently I have bought several used bra's, sometimes with matching panties from ebay.
Although I have not bought loads I have been surprised by the understanding nature of some of the ladies.
One lady guessed I was a guy and asked me if I had a fetish and would I like her to wear it for a day before the sale, I got it smelling of her body.
Another lady I collected from her house and she asked me why i wanted it, when I told her it was a fetish thing she snatched it from me and left the hallway. I thought she was angry and had gone to get her partner or something but she shouted me to wait there. Quickly she came back empty handed but then pulled up her top and let me see her wearing it. I wanted to touch but she turned away and left me only to return with it in her hand, took my money and said goodbye.
I have also been offered photos of the bra being worn for a little extra cash.
I have had a couple of rather upset women too who are not so pleased.
Some like to ask why I want it, in some detail and others don't seem to want to know but are happy and even offer future sales.
I always buy from strangers.
I also make videos of myself using them, always planned to upload them to one of those free xxx video sites anybody can upload to but not done this yet.
I get a real thrill of using a strangers bra in this way, especially if I get the chance to meet them briefly at the sale, knowing they know what I will do with it is a huge turn on, almost as much as the feeling of the fabric against me. I crave the owner to watch me.
I now have a fantasy that some obliging lady will ask me to demonstrate what I do with it in front of her.
Apart from this interaction with the sellers I do not involve anybody else neither am I pushy, pervy or offensive.
If it wasn't for these obliging ladies I do not know what I would do to satisfy this need.
I am very happy with my fetish, it causes me no problems at all to date but what do you think?