Watching her at it

My wife and I have just got back from a session. she has written on here before of her experiences and I have written about the first time I saw her with another man, so I thought it only right that I tell what happened tonight.
As you may recall, my wife has been giving 'lessons' to a lad she works with, and has been coming home full of life and his and others spunk.
I've been wanting to watch her getting fucked again for some time, so we arranged to meet the lad and a mate of his at a local car park to us.
We got there and waited, but it was starting to rain, and I wondered if that would put him off. The wife texted him and got the reply that he was on the way.
She was starting to get frisky, telling me how she enjoyed all this and how horny it made her. As we sat waiting, I wondered if I was doing the right thing, but she seemed happy enough and I enjoyed what I had seen before, so was there a problem?
Shortly after a car pulled into the car park, and my wife said "thats him" and got out telling me to come across when I was signalled.
I could see two figures in the car as she walked across towards it.
As she got next to it a figure got out, opened the back door, she got in and the figure got in after her.
After a couple of minutes, the light came on inside, and I saw a hand wave. I took this as the signal, got out and walked across.
I got next to the car, and looked into the back seat area. I could see my wife was now naked from the waist down, legs spread wide with some guys fingers pushed up her open cunt.
The guy in the front opened his window and asked if I was OK?
I asked him what he meant, he asked if I was ok watching my wife with another man.
I said yes, but I'd like to see more.
My wife said "Thats enough fingering, let him see something worthwhile"
The guy then moved between her legs, but she stopped him and told him to get out. She then got out of the car, he followed and after he had got out, moved her round so she was facing the side of the car and moved behind her.
There is something very erotic about seeing a woman bent slightly over, by the light of street lights, especially when it is my wife with a hard cock poised to enter her.
He took hold of her hips and pushed into her. She gasped and opened her legs wider to take him in and he responded by starting to fuck her harder. Evert thrust was making her gasp and it wasn't long before she came, with the guy soon after her.
He pulled out and zipped himself up. The second guy got out and went close into her and whispered something. I couldn't hear what it was, but my wife responded with "You dirty bastard, but OK, if thats what you want to do"
She turned round to face the car again, this time putting her feet as wide apart as she could and bending over as if to touch her toes. She put her right hand out to steady herself against the car, as the second guy stood behind her and started to finger her from behind. The position she was in allowed him to get four fingers in, which he kept there pushing in and out and twisting them round. I heard my wife say "now would be a good time". He pulled his fingers out and moved them up towards her arse. He began slowly pushing one finger into her tight ring and then added the others. She started to make noises of pleasure, as he slowly fingered her arse and then moaned even more as he put fingers from his left hand into her already stretched fanny.
I could tell by her breathing she was close to orgasm, when she said "Do it now, before I tense up".
He pulled his hands out of her and she straightened up, but he was then behind her with his cock in one hand, the other forcing her cheeks apart.
She moved forward and gave a little moan as this guy pushed his way with one long thrust into her backside.
I moved forward and stood watching as another mans prick pummeled my wifes tight arse.
"Do you like watching me up your wifes arse? I'm going to fill her up and then she is going to suck me clean"
I heard and watched my wife come for a second time, and then she said between gasps "cum in me, please"
The guy then started to pump harder and then gave a couple of grunts and pulled out.
My wife immediately went down on her haunches in front of him, taking his cock into her mouth. He put his hand on the back of her head, pushing her down onto his cock.
As I watched this, he said "You have got a fucking dirty wife, I'm going to have her again, with a few more of my mates. She'll come back to you so full up, it'll be spilling out of all holes, mate"
He let go of my wife's hair and she stood up. She had a very satisfied smirk on her face, as she opened the back of the car to get her clothes out.
As she did so, the guy who had just finished fucking her, smacked her hard on the arse and said "I'll see you next week"
She stood up after putting her heels back on, and said " You and all your mates, then we'll see who wears who out".
She then walked across to our car, still naked below the waist and got in.
As we drove home, my hard on was raging. I have not been allowed to do anything with it until I had finished this. I'm now going.