I was working in the garden when I heard my neighbour call out for help. She was in her late 60's I guess ( I was 38 then). She was a widow, her husband having passed away a few years ago. She called to me telling me her sink was blocked and could I help. I said yes and made my way to her house. The sink was blocked and I opened the door beneath the sink to dismantle the S bend. As I was doing this, my neighbour stood close to me chatting about how greatful she was and how this was the sort of job her husband would do. I moved my head slightly to tell her not to worry about it and I glanced up towards her. She was wearing a housecoat and it came to about her knees, I could see up between her thighs. She was wearing a sheer pair of white panties which were tight around her ample frame and I could see the shadow of her pubic bush. The sudden sexual jolt that shot through me was intense, my cock hardening as I looked up. She kept moving back and forth rocking slightly on her feet not realising the show she was giving me. I fixed the problem of the sink and standing up next to her I told her it should be ok. She smiled and nodded moving towards the sink to test it. I leaned over her to turn the tap on pressing my groin against her bum as I did. Everything seemed to stop. She didn't move, didn't speak. I just stood behind her gently grinding, my cock throbbing and flexing against her body. She asked if I was okay. I just grunted and slipped my hand down the side of her hip, bending a little I curled my fingertips under the hem of her housecoat and started pushing it up slowly. She just stood there, letting me. I could feel her trembling slightly as my fingernails brushed against her skin and then across her nylon panties. I could feel heat radiating from her body as I slid my hand between her thighs. She sighed and parted her legs as I rubbed her, my forefinger pushing the material of her knickers into the folds of her pussy. We both still said nothing just our breath quickening as I fingered her. She bucked against my hand pushing back harder as I hooked a fingertip into her panties tucking them aside to gain access to her moist hole. My finger slid in deep, making her gasp. She rode my finger for about 10 minutes, her body shuddering, her breath ragged as she came to a climax. I followed immediately, the sheer eroticism of what I was doing making me cum in my shorts. Leaning in I kissed the back of her neck, " you made me cum" I whispered. She just moaned and stood as I moved back a little. She turned to face me looking questioning at my face. I smiled and bringing my hand up traced the count our of her cheek. "Thank you" I said. She smiled and nodded. I tidied up and left. Nothing more was said about what happened that day although , now and then, I replay what happened and regret not taking her to bed.