My girlfriend and I have been staying with my parents here in Tampa since the 4th of July. My family has been very generous and hospitable to her during that time. Naturally, her response was, “我觉得不好意思.” Then she asked me how to say 不好意思 in English.
I usually find 不好意思 pretty easy to translate, as it can often correspond to “sorry” or “excuse me” in English. When you’re a little late to a meeting, you can say 不好意思 (sorry). When you eat the last cookie and then somone else wants one, you can say 不好意思 (sorry). When you bump someone on the subway, you can say 不好意思 (sorry).
But in this case, my girlfriend’s usage was meant to express something like, “your kindness is too much,” or “you’re being so nice that it makes me feel too indebted.” And she wanted me to come up with one easy word or phrase to translate. When I couldn’t, and I asked for help from my sister, and she couldn’t either, my girlfriend just laughed: “you Americans never feel 不好意思!”
Pei sei is apparently a Taiwanese coinage also meaning 不好意思. According to my source, by speaking fast, the Taiwanese ran the 4 syllables together so much that they became two: pei sei. I thought that was kinda of interesting.