Watching My Neighbours

i own two adjoining houses one ii live in the other i rent out. New tenants moved in a few weeks ago. they are in their early 20s. a nice couple. The arrangement of the kitchens is that they are both i n extensions facing one another. To cut a long story short it was early evening and just starting to go dark and i went into the kitchen for a can of beer, Ididnt need to switch on the light but noticed the light next door was on. I soon noticed that the girl was leaning over the sink and her partner was stood behind her and it looked like he was fingering her pussy as his hand was moving up and down. She then noticed me watching her and smiled at me. I smiled back at her.He moved closer to her put his hands on her bottom and then moving even closer easing his cock into her.She took a firmer grip of the sink as her started moving in and out of her. This turned me on and i took my cock out and started wanking. moved a little b ack from the window so she could see me with my cock in my hand. I didnt last too long an d soon came but he carried on pumping his cock deep into her until he was ready to come when she turned around and fell on her hands and knees to take his cum in her mouth. A couple of minutes later he left her there, She got up off her knees and grabbing a kitchen towel to wipe the spunk off her face. She waved to me as she left the room. I spoke to her the next morning but neither of us spoke about the night before, To finish i have seen her fucked quite a few times in the kitchen and I would like to be a fly on the wall in their bedroom while he gives her a good fucking.