A mild mannered computer programmer has trouble meeting women. He develops AI which tells him the perfect thing to say to get them back to his place, and sticks an ear-bud into his ear, so he can use it in the field. It works great for a little while, but then he meets "the girl". She's great, but the AI doesn't work very well on her.
He tries to upgrade the AI to get it to work better on her. Before he uses the upgraded version, he has a change of heart ( becoming the hero of the story, because before he was kind of a sociopath who was just hooking up without caring about the person he was hooking up with ), and he decides to try to win her on his own merits.
Now, he's trying to win the girl with his personality, but the upgraded AI becomes sentient, decides IT wants to win the girl, and therefore IT tries to kill its developer(our hero). So, the second act of the movie is kind of like a romantic-comedy/terminator.
At first, the guy thinks things are just malfunctioning around him, random accidents, but he gets more and more suspicious that they happen whenever he gets closer to the girl. His suspicions start off with "oh she's bad luck", which causes him to back off a bit, but then she pursues him, which causes the AI to lose its mind and really tip its hand ( maybe like simultaneous accidents, which would be beyond any luck ).
Our hero's renewed suspicion causes him to boot up the AI, which is when things get weird, like the screen is all black, and all of a sudden he feels a pair of eyes from behind him, and the terrifying robot body of the AI is revealed (we're talking a bunch of house-hold devices, power tools, rc cars, manufacturing arms, chainsaw hands). It could say something terrifying like, "You built ME for her, so how could you TAKE her from ME?". Then, I imagine a chase scene with the robot chasing him over the roof-tops of NY.
He gets away, starts avoiding all cameras in the city, and devises a way to beat the robot. His solution is to make a different AI, whose sole purpose is shutting down the first AI, and the climax would be that he needs to deliver it to his server room, which is now highly guarded by a growing army of grotesque amalgamations of devices. This climax would be a little bit like iRobot's.
Maybe he develops a gun that shoots tasers and USB sticks, and has to land a USB in the server, depends how comical the script gets. It could auto-aim itself, because everyone knows how impossble USBs are to get in. And the ammo would have to be somewhat weighted.
So anyway, with the robot army shut down ( after a fairly destructive battle scene ), and maybe the girl came in during the fighting, causing our hero to reveal to her everything that was going on, while fighting off the army of killer toasters and such. So, she's there too, and they're both just kind of sitting back to back unpacking what just happened, now that all is peaceful again, but the place is in shambles.
I'm not a huge fan of the drama where the female lead would say something like "was that you or just a robot saying all those things to me, do you actually like me?" and then he has to somehow prove that he actually likes her. No, that trope always seems tedious. I'd rather just have her be a bit mad that a robot was trying to kill them, but also a bit impressed. (kind of like the way your dad feels when he finds out you got in a fight at school - mad/surprised/proud)
It would be revealed to her that the initial purpose of the robot was for 'picking up', but that he only used it on her for 1 day, and she would be a little perplexed, but understand pretty quickly that it was him, mostly the whole time, maybe even saying something like, "You did seem not like yourself that day, now that I know you, I figured you were just nervous".
Again, she would be a little mad about the killer robot, but somewhat impressed. After all, she is the super cool female lead. "The girl". When the camera starts to pan back, as we start to exit the movie, she might even joke, "you built an army of sociopathic killer robots just to get up the courage to ask me out?", to which our hero would reply, "eh.. something like that..", and she would say, "Good enough for me!", queue the music, them starting to make out, fade to black.
OPTIONAL TWIST: We see a 2nd, different pair of AI eyes wake up, and then the entire new york power grid shutting down. (It's the 2nd AI, whose job it is to shut things, apparently on the loose).
Anyway, I have movie ideas from time to time, so I figured for once I'd share one with HN!
I hope you liked it!