Friends mum wants more than a few sockets fitting

the bathroom door opened and she slipped quietly inside, grabbed my overalls and disappeared I was a young electrician back in the 80's and newly qualified, I had a friend who I went drinking with and he had a girlfriend who also drank with us occasionally. One day he told me that her parents wanted some extra sockets fitting in their bungalow and asked if I would do them for them, it was a chance to earn some extra cash and possibly get more work in the future.
I went to look at the job and it was really easy, the bungalow had hollow floors and there was even a trapdoor to access the void below, I decided to check it out and dropped down into a space a little over a metre deep, it was them that I realised that it was very wet and muddy down there and I would need to take precautions to avoid getting messy on the day I did the job.
Having considered all options I decided that the best plan on the day would be to remove all my clothes except my boxer shorts and put on a pair of overalls, I could then change back into my clothes after finishing the job. It was arranged that I would carry out the work on one of my days off, he'd be at work but his wife would be at home to let me in.
I carried out the work and as I had suspected ended up quite muddy, the lady of the house suggested I take a shower, she knew nothing about me having changed out of my clothes before I started and while I was in the shower she came quietly into the bathroom and picked up my shorts and overalls, she then disappeared.
I finished my shower and towelled myself dry, " I've put your clothes in the washing machine, they won't take long, come into the lounge for a drink when you've finished" she called out as I heard her passing the bathroom door.
I took my jeans, socks and T-shirt out of my bag and got dressed, I picked up my bag and headed into the lounge, on the table was two glasses, a bottle of scotch and a bottle of mixer, "won't be a minute, why don't you pour us a couple of drinks" she called from somewhere in the house, then added, "I'll be in in a minute".
I poured a couple of scotch's and sat on the couch, soon after the lounge door opened, "your clothes will be ready soon and you can get dressed" she said and entered the room clad only in a skimpy basque, panties, stockings, suspenders and high heels.
Her face was a picture when she saw that I was fully dressed, she was just about to sit down when I saw a car pull up on the drive, "does your husband still have that red Vauxhall?" I asked (he'd been talking about changing it) "yes but he won't be home for a few hours yet" she replied, "why do you ask?" I glanced out of the window once more, "well one has just pulled into the drive and a bloke is getting out of it" I replied. She glanced quickly towards the window, "oh shit, Dave" she gasped, then legged it towards her bedroom.
The front door opened and in walked her husband, seeing the two glasses and an ashtray on the table he just smiled, " I see she's looking after you then, did the job go alright?" I nodded, "yeah fine, it was a bit muddy but I brought a change of clothes, in fact she's put my dirty stuff in the washer, she told me to have a drink while it was being washed" he nodded, "ok, I suppose I'd better pay you then" he'd just handed me the money when his wife re-entered the room, this time she was wearing a pair of jeans and a top.
We had a drink and a brief chat about some more work, finally my overalls were washed and dried and I packed up my gear and left. How close was that, if he'd have been ten minutes later he'd have caught me shagging his wife!
I often wondered if she'd planned it herself or if he knew about it, I never got chance to go back and see what would happen, I changed my job and left the area shortly afterwards.