second thought
noun [ C ] uk/ˌsek.ənd ˈθɔːt/ us/ˌsek.ənd ˈθɑːt/
without a second thought 重新考虑
If you do something without a second thought, you do it without first considering if you should do it or not.
She'll spend a hundred dollars on a dress without a second thought. 她会毫不犹豫地花100美元买一条裙子。
have second thoughts 改变主意;开始怀疑
to change your opinion about something or start to doubt it
You're not having second thoughts about getting married, are you? 结婚的事你没改变主意吧？
on second thoughtsUK (US on second thought) （表示要改变主意）又一想，转念一想
used when you want to change a decision you have made
Can I have a cup of coffee, please? - actually, on second thoughts, I'll have a beer. 请来杯咖啡——说实话，我改主意了，来杯啤酒好了。