This was an unplanned thing, but I was just taking advantage of the opportunity as it presented itself to me. This was a little naughty trickery.
She was a good Christian lady, unmarried, and a little naive. We were all out together, after work. She doesn't drink much, and I'm driving, so I'm not drinking much either, but I've still had a couple of drinks. Since she's not really the drinking type, she is only out to be sociable and is not going to be staying all evening - I am in the same kind of situation, so I have promised her a lift home after talking her into coming out 'just to be sociable'. As I have said, she's not the drinking type, so her couple of glasses of dry white wine are comparatively a lot for her.
My motive for chaperoning her is not completely altruistic. She is single and unattached. Although her religious views make any hanky panky unlikely, religion has never been a completely foolproof preventative. I am always interested in possibilities and what may be achieved. I have found that religious prudishness about sex is often just a front, and a little imagination in navigating relationships can often find a way through that.
As agreed, after about an hour and a half, I took my leave and offered to take her home. She normally has a difficult journey, since she does not drive, so this is actually nice and easy for her, and the wine has relaxed her. We chat a bit as I drive her to her house, and I mention, as a deliberate ploy, that maybe I have had a little more to drink than I should, so that, when we arrive, she naturally offers to make me a coffee and give me a chance to sober up a bit before I drive on home. The invitation into the privacy of her own home gives me the 'foot in the door' situation that I can exploit.
So we're sitting in her living room drinking coffee, eating cookies and chatting. I'm confiding in her, and this is building up an intimate atmosphere between us. The alcohol, which she is unaccustomed to, has relaxed her, and she is laughing as I joke with her. I tell her how nice it was to be able to get out after work with people, even for a short while and relax and how this is difficult for me sometimes, because the wife easily gets jealous.
She says that the wife must know that she has nothing to be jealous about, so I confide in her further and explain how bad it would be if Sally knew that we were sitting like this together - she would never understand that it was quite harmless. She repeats that Sally must know that she has nothing to worry about. I agree and confide in her more, building up the feeling of closeness and camaraderie between us.
Then I say that I ought to be going. She asks me to stay a bit longer - she's enjoying our chat, and she's also concerned that I am ok to drive. I say that it is better that I go, all things considered, but she says that I ought to stay just a bit longer, just to be certain.
I wonder if she might, even subconsciously, think that something might happen. My cock, always listening, gets a message. It gets ideas easily.
Now this is a tricky bit. I am feeling horny and my cock is stiffening, thinking of what it is I might be going to do if I get the opportunity. She is saying that we are just friends and Sally has nothing to be worried about. I say that I'm not too sure of that, and I'm feeling awkward. She says that I shouldn't feel awkward, and if something's worrying me, then maybe she can help.
This is the sort of situation I have been trying to create - slightly ambiguous. I want what happens next to appear as just a misunderstanding. I say that perhaps she can help, but I don't want any misunderstandings, so I'm reluctant to involve her. She says she would be happy to help out.
I do wonder if she is really this innocent, or if she might also be secretly hoping.

This is ideal, enough ambiguity that I can work with, and the intimate atmosphere works for us both. My cock is already stiff in my trousers - I am surprised she has not noticed, but she probably does not think of such things. The situation is full of potential, and so are my pants.
The next step is a pure delight.
"If you are sure," I say, standing up and reaching for the front of my trousers. Before she realises what I am going to do, my pants are undone and my thick cock springs out in front of her - it stiffens more, once given freedom and air to grow to its full glory, with the thrill and naughtiness of what I am doing and - boy, is she embarrassed!
I wonder if she thought that might happen?
So there I am, standing up with my cock fully erect, obscenely bobbing in front of her face. She can see the swollen head and my peehole, which might be visibly leaking a little precum; I can't see, but she can. She is speechless, and her cheeks are turning red.
'Oh my," she manages to say, and, of course, I realise that I have made a terrible mistake. (Oh, No!)
I start apologising, saying how awful I feel. My cock is still stiff, and I do not put it away. I say that probably I had better go and apologise again for the misunderstanding. She says it's alright, but that she thinks I had better go too. She has not stood up, but is still sitting - she could not stand up without touching my cock, so she is kind of trapped.
I tell her that I cannot go like this - it will be just too uncomfortable, and I cannot drive in this condition. I say that I will have to take care of it, and I hope she doesn't mind. She says that I had better do whatever I need to and then just go. I apologise again and start masturbating in front of her. Of course, I could have excused myself and gone to the bathroom, but that was not what I wanted. In the heat of the moment, she seemed to forget that I could do that as well, but once I'd started masturbating, she did not stop to suggest this - she actually seemed rather interested in what I was doing.
Anyway, I sped up the action - it felt good jerking off in front of her like that. The next stage was completely predictable, but she didn't seem to foresee it - I came, quite forcefully, splattering cum all over her. She was horrified, and I was even more embarrassed and apologetic, and everything. (Oh, dear!)
It was terrible, I left feeling awful about everything I had done to her, apologising continuously - what must she think of me?
"You'd better just go," she said with my semen still dripping off her face. I put my leaking cock away, did up my trousers, and left.
"I'm sorry," she said, as I left the room and let myself out.
Big bunch of flowers for her at work the following day, to say sorry, and we agreed between us that we would say nothing to anyone about what happened - after all, she was just as embarrassed about it all as I was.
There was some comment in the office about the flowers, which I explained away as an apology for an act of clumsiness at her house, implying a broken ornament, or something.
Again, willingly taking all blame and apologising most extravagantly. At the office, I appeared as a true gentleman; she enjoyed being the beneficiary of my most sincere public apology for the secret fact that I had deliberately jerked off over her.
Strangely, this shared awful secret created a strong positive relationship between us.
Fantastic Result!
