My ex wife/Mistress used to make me wear her panties and piss myself whilst on cam to humiliate me and I hated it.Then one hot day we went for a walk in some woods near to us and she made me wear a pair of her panties under some white shorts.An hour into our walk I needed a piss but when I asked for permission I was refused.One hour later I was really really desperate but was refused once more but could not hold on anymore and just wet myself.Whether it was the fact that this was real public or not and really humiliating with people seeing me I don't know.But as the warm piss was running down my cock and some making it's way into my ass crack I started to get turned on and got an erection.Since then have I have loved pissing in panties and masturbating once finished pissing.

Been there, done that