It is nice of them to stay with you and help, but I would question the culture in this workplace. The proper solution from my point view would be to say: "Let's go home and continue tomorrow together".
That's the culture at my workplace. While there are a few developers who stay late, the vast majority of us have no difficulty walking away and going home. We even encourage it.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.