看绝望的主妇学高频短语：On the sidelines

Sit on the sidelines：In a position in which one is not actively participating in something, or in other words：observing rather than taking part. If you are on the sidelines in a situation, you watch it happening but are not directly involved and cannot influence it. （置身事外、袖手旁观）
“On the sidelines”这个俚语前面可以用很多动词（Sit, stand, stay,remain,wait…）

E.G.1：Some people spend their time on this planet just sitting on the sidelines waiting for something to happen to them before it’s too late.
翻译：有些人一辈子只作壁上观，坐等着自己生命结束前会有惊喜出现。（摘自美剧『绝望的主妇』S01E12）

E.G.2：Well, if you’d like for her to remain in office, you’ll take my advice and just stay on the sidelines for now.
翻译：如果你希望她继续执政，我建议你现在开始暂时保持置身事外。（摘自美剧『越狱』S02E06）