Hi, Edison, it seemed should be about the difference between "おっと(夫)"and"しゅじん(主人)"?
Basiclly, both of them means 'husband'.I think compared with"おっと(夫)", "しゅじん(主人)"is just a honorific.
They used in different situation.
主人(しゅじん)=my husband. Talking about own husband to other people formally
△私の主人は中国人です。-My husband is a Chinese. (introduce own husband to co-worker or boss)
ご主人=your husband. Talking about listener's husband by showing respect
△ご主人は中国人ですか。-Is your husband a Chinese?
おっと: it's a neutral word.I think it's easier than しゅじんto use.Because you don't need to think if or not it should be added "ご" ahead.
△私の夫(おっと)は中国人です。
△あなたの夫は中国人ですか。