What in the world did they think they were doing?
他们到底认为自己在做什么？
One major problem did present itself, though.
不过，确实出现了一个重大问题。
Someone might find out, and that would never do.
也许有人会发现，那是绝对不行的。
Only then did she realize the stress he was under.
直到那时她才意识到他所承受的压力。
What sort of person would do a thing like that?
什么人会干那样的事呢？