I’m 51 and my wife’s mother Sandra is 70. She still has all the right curves in the right places and she is very touchy feely whenever we meet. Although nothing has ever happened between us I often think about her whilst I am giving the wife one. We were invited to a fancy dress party and the theme was 1940’s so I had a month to find an outfit. Sandra suggested looking in the charity shops and it paid off because I found a perfect suit but it did need adjusting. She also said she could alter it for me because back in the day she used to be a seamstress. The wife was at work and I arranged to go round to the in laws with my suit to get measured up. Didn’t know how it was going to work but before I went I showered and had a trim downstairs then put on some tight white boxers that showed off a nice bulge. Got to her house and Dave her hubby was sat downstairs. He said we were expecting you and Sandra came in from the kitchen. She gave me the usual hug and kiss on the cheek and I sneakily held my hand on her bum for 5 seconds. She told me everything was set up upstairs in the spare room so we went upstairs. I laid my suit and shirt on the bed and she came in with a tape measure around her neck. “So first of all I need to measure you so take your jeans and top off and I’ll get to work “ I undressed in front of her and was stood there in just my boxers and socks. “Right stand up straight “ and she went to work measuring my chest and waist. “Now I need your inside leg” and she knelt down with her face directly in front of my bulge. “Which way do you dress sir” she asked with a smile on her face. I looked down at her and stuttered “Oh, err, well err this way” and i ran a finger along the outline of my penis which was hanging to my right. She smiled and said “Oh yes I can clearly see it “ She then held the tape measure to my groin an ran the tape down my leg. She then measured the other side making sure the back of her hand was touching my testicles and penis. “Now I need to measure you with the suit on” she said so I got dressed into the gear and she did the same again. She had enough measurements and said she’d need to see me in a couple of days. I asked her which day was better and she said Thursday because that’s when Dave plays bowls so we arranged for Thursday. Thursday came and I went round with my shirt and tie to hopefully try everything on. Again it was another pair of tight white boxers that clung to me. I got to their house and sure enough Dave was out and going to be out all day. She told me she just needed to measure me again just to double check so upstairs into the spare room and undressed down to my underwear. Same measurements chest, waist and then knelt down in front of me to do the inside leg. “I can see you still dress to the right “ she said and then unexpectedly ran a couple of fingers along my penis. Well I’m afraid this had an effect on me and I developed a full erection. There was obviously nowhere to hide and my boner was now about 3 inches away from her face. She smiled and just said “Well, that’s going to get in the way a little bit “ she then hooked her thumbs st the side of my boxers and yanked them down past my knees to my ankles, allowing my fully erect cock to bounce free and angrily point towards her face. “Ooh you’ve got a big one” she said with a smile and she cupped my balls making my cock swell even more. Her fingers ran up my shaft and she began to wank me off. “Oh Sandra I’m not gonna last long” I said and she just carried on talking dirty “I want you to cum on my tits” she said and unbuttoned her blouse to give me a big cleavage to aim for. I managed to hold on for maybe a minute and I just had to release everything I had. There was 3 heavy ropes of cum which mainly landed on her tits and another 3 or 4 pulses which just dribbled out. “I think we need a shower “ she said and stood up and undressed in front of me and lead me to the bathroom. The old chap didn’t let me down and she whispered in my ear “We need to go back to the bedroom now.....”