There seems to be several problems. Not entirely sexism.

1. Founder's wife asked Horvath out and gave her a lecture about who is the boss. Probably out of jealousy.

2. Founder's wife physically inanimate Horvath, making her unwelcome and scared.

3. Founder did not stop the wife and protect his wife.

4. Horvath was approached by a male co-worker and according to her her rejection had caused tension between her and that co-worker.

5. Horvath's partner is also a Github employee.

6. Another founder tried to step in but the situation didn't really resolve.

7. Horvath felt male co-workers gawking/staring/looking at female co-workers hula-hooping while sitting in a couch looked like someone visiting a strip club.

This is more like a failed company management than sexism at work.

A partner can help his or her partner looking after/helping/running a company even as a non-employee. He or she could send employees your homemade cookie or send them birthday card. It's okay to share thoughts with partner how to run a company, how to resolve people-people problem.

But the founder should not let his or her partner to intimate anyone: HR, executives, managers, engineers. This type of behavior, I thought I would only see them in drama (well I guess you can say something about WhiteHouse...)

The founder accused Horvath for bringing love affair into the company because she was/is dating an employee. The founder has a good point: try to avoid dating someone working with you. It's a beautiful story; but you can cause all sorts of mess. See this childish engineer who was rejected by Horvath became angry at her and started ripping her code out. I have read about Github's open culture, but hey, how could anyone do that!? And yet no one seen to care internally at all because he's a popular figure in the company. Well, I can't say everyone in that company is shit because there is also a rank in any organization. I wouldn't go against someone senior or more popular unless I have to. This is also a bystander problem: unless we have to deal with it, let other people and the people in the story deal with the situation.

While the founder is right about avoiding dating someone in your own company, he couldn't see that his wife (effectively meaning his own family problem) was also leaking into the company's daily operation.

The other founder tried to help Horvath. The founder apologized and tried to restrain his wife from sitting across Horvath. But the wife continued to "spy" on her. She was welcomed to do whatever she want to do. Horvath tried to ask other executives to help for the very last time and none worked out. Either the founder was scared of his wife (love her so much he didn't want to yell at her) or none of the executives really care. Someone with management skill should have step in and tell the founder "stop letting your wife to come in!"

Apparently, people fear the founder? and the wife??

Regarding the strip-club comment, I don't know the best way to avoid it. I, as a male, try to avoid staring at another female because I fear someone like Horvath accuses me of sexism. Maybe the guy was just bored or thought that female worker was beautiful. Staring at someone shouldn't be counted as sexism. It's hard. Would a female staring at a beautiful male count as sexism?

I am not saying there is no sexism in work place, but I think Horvath's overall sexist experience might have been influenced/augmented based on her treatment in the company (no one stop the founder and his wife abusing power).

But hey, I am just reading off the article. Her experience could be worse! I do feel bad for all the intimations she had to go through. I felt really bad as I was reading the article.

Final point:

Horvath then told her partner, also a GitHub employee, about what was happening. She warned him against being close to the founder and his wife, and asked him not to relay information to them.

I have a mixed feeling. If I were in his situation, I would try to sort out the problem with the founder myself. But now that I read about it, I guess in the future, if I were in a similar situation, I would not talk it out until situation gets worse.