I love going into the bathroom after Zoe has just had a really big dump. I love the smell and the warm seat when she's been in there for ages. Last night I got home from work busting for a crap and Zoe was in there taking one of her marathon 5 day dumps. She took ages and I really had to go which I found exiting. When she finaly came out an hour later I was nearly shitting my pants and I ran in holding my bum desperately trying trying not to lose it. The smell inside hit me and it was a mixture of sex and poo so Zoe had been masturbating in there. That really got me horny and I sat on a very warm and sweaty toilet seat. As some as I did I started to go really quickly as I was so desperate and it was a huge relief. It was then I noticed Zoe's knickers were on the floor. They were wet in the crotch where she was so horny and I wrapped them around my hard penis and started to rub myself slowly. I came quickly as I was so horny and once I recovered I wiped and flushed the toilet.