wǒ běn lái bù xiǎng qù de zài shuō nà tiān xià wǔ wǒ yuē le yá yī què shí zǒu bù kāi

我本来不想去的，再说那天下午我约了牙医，确实走不开。

I didn't want to go in the first place. Besides, I had a dentist appointment that afternoon and really couldn't get away.