Added in response to : 'It wouldn't be sexist if he wrote "how I taught my girlfriend to program". Imagine if it said "how to teach your black friend to program". Why only black friends?Why only girlfriends?' ----- Sorry, trying to mix race in this just to raise issues is simply not going to fly with me. He has a girlfriend and wants the world to know they both are geeks that want to do something together. There is no plural in that title unlike the way you distorted it, it is a common way to use the infinitive, what is your problem with that, can't you just read it for what it is. Don't you see there simply isn't traction for a sexist cavalcade on some guy that is over the moon because he found someone that will put up with his 'teaching'. How can you miss something so simple to the point you are trying to project discrimination on some couple doing something together.