擦屁股在英语中一般翻译为 "wipe one's butt" 或者 "wipe one's behind"。这个说法源于日常生活中人们在洗澡后用纸巾或毛巾擦屁股的情况。例句如下：

After using the bathroom, I always make sure to wipe my butt thoroughly.

Don't forget to bring some toilet paper so you can wipe your behind when you go to the bathroom.

擦屁股的英文说法可能听起来有些粗俗，所以一些人会选择使用更加委婉的说法，如 "clean oneself" 或 "wash oneself"。例句如下：

After using the bathroom, I always make sure to clean myself thoroughly.

Don't forget to bring some toilet paper so you can wash yourself when you go to the bathroom.

但是，无论使用哪种说法，都应该注意在正式的场合中避免使用这些说法，因为它们可能会被认为是不礼貌的。