What constitutes substantial performance in your case? You'd first have to establish that there was indeed a contract, a meeting of the minds. If you said, "I'm gonna make you come," and she said, "Make me come, make me come hard," and you said, "I'm gonna make you come hard," and she said, "I'll fuck you good, I'll make you come," and you said, "Wait, not yet," and she said, "Come on, do it," then I think it's obvious there was a contract because both of you promised to make the other come, and everyone knows that even if a guy says, "Wait, not yet," he's pretty much almost there already. It's a done deal. But the woman, that's a different ball game. As a guy, you gotta pay to play. You made a promise to get the job done. You had work to do.

For the sake of argument, let's say there was a contract. What's substantial performance? If you had said, "I'm going to make love to you," we'd just run down a checklist of things you did toward that goal: positions, behaviors, actions taken. Even several small spastic movements in quick succession would have, arguably, constituted "substantial performance," although getting a good ruling on that mostly depends on the gender of the judge.

However, because you promised to make her "come," we need to look at her subjective experience. We need to search for evidence (verbal, physical, or otherwise) of orgasm. An "ooh" or "aah" is clearly not enough. "That's good," is probably indicative of pleasure, but we're looking for pleasure that rises to the level of orgasm. That's a high pleasure standard. Guys are in a tough spot. In situations where it's a close call, a guy often has to take the woman's word on her subjective experience because there are so few reliable objective indicators.

Given that, in your case, she voiced her dissatisfaction in no uncertain terms, you have to determine whether your performance induced substantial pleasure, if not quite orgasmic pleasure, or, alternatively, whether your performance induced pleasure substantial enough for a reasonable woman to have called it a night and faked the orgasm. While a reasonable woman cannot experience an actual orgasm and remain reasonable, a reasonable woman can fake an orgasm and still get to sleep at a reasonable time.

Should you ever get your act together and make a reasonable woman come unreasonably, you will probably endure blows to the head, lacerations to the back and buttocks, and perhaps even ferocious bites to the neck and biceps. This is clear evidence of decidedly unreasonable behavior, as well as clear evidence of an induced orgasmic state. That your performance in this case induced in your girlfriend a desire to sue is, instead, evidence of decidedly reasonable behavior.

So you're screwed. Because she wasn't.

CREATIVE COMPLAINTS DEPARTMENT
Curious: I heard rumors about all the weird ways civil attorneys serve papers on the parties they're suing. What weird things have you done?

Mr. Lawyer: While every maverick attorney would prefer that a memoirist report in epic terms his feats of ingenuity, I will take the task upon myself and divulge a short list.

I once painted the text of a complaint on a used car and had it delivered to a used-car salesman a client was suing for fraud.