My wife had discovered me in her undies again and as I had promised the last time would be the last she packed her bags and left. I had always had the urge to dress in underwear and had borrowed hers numerous times, she went back to her mum. A couple of days later my mother in law called round and came in, she said my wife had told her everything and that I wore her sexy undies. At first I was embarrassed but as she spoke to me she sounded reassured and wanted me to show her what I looked like, eventually I agreed and she went to make us a cup of tea. I had bought some new stuff and dressed in black stockings and suspenders, black high heels, lacy black bra and sexy slky black french knickers and sat on the sofa. She came back with the tea and made an mmm sound and sat down next to me. "stand and twirl for me" she said and I stood and turned in front of her, she adjusted my stockings for me and said I did look sexy and to sit back down next to her. Her voice was low and she explained that unlike her daughter she liked her men in silky sexy undies and put her hand on my stockinged leg and moved up along my suspender. By now my cock was hard and making a silky tent out of my panties, her hand moved inside and began to wank me slowly. I didn't last long and I came in my knickers, she whispered I was a dirty boy in my ear then pulled my soiled panties down and off and held them in front of me ordering me to lick them clen which for some reason I did as I was told. She the grabbed me and marched me to the bathroom where she made me wash my panties out all the time telling what a dirty boy I was before she left and telling me she would be back again tommorrow and expected me ready in my undies for her. Can't wait .......