stand you up 和起立无关
Stand up与不同的介词搭配有很多截然不同的意思，to stand up with someone 的意思就是和某人跳舞。后来在婚姻领域，stand up展现了一副在临举行婚礼前被人抛弃，站在教堂祭坛的样子。自此之后， to stand someone up 便指对某人做出了浪漫的承诺，但最终却没有履行。
stand you up
stand someone up
You usually use stand someone up to talk about a situation where two people who don’t know each other very well just started becoming romantically involved with each other and one person agrees to go on a date with the other but purposely (or, more rarely, not purposely but knowingly) doesn’t show up for the date without telling that person they wouldn’t be there. I know this is kind of confusing, so let me just tell you a little story to make this less confusing:
你通常使用stand someone up这个短语表示两个本来不熟悉的人准备进入一段浪漫的关系，然后其中有人同意去约会，但故意(或者极少情况不是故意的)在没有告知对方的情况下没有去约会。我知道这有点让人迷惑，所以让我告诉你们一个小故事让它不那么迷惑：
Harry just met Sally. He thinks Sally is a very pretty girl, so he says, “Sally, will you go to the movies with me?” Sally nods yes. She is mute, but she is very pretty, and she very much wants to go to the movies with handsome Harry. They smile at each other.
Come Friday night, Harry is at the movie theater waiting for Sally (he didn’t pick her up because this is the kind of date where they were going to meet at the place). Sally heard a nasty, nasty thing about Harry from her friend Joe, who says that Harry is a rapist and is picking Sally to go on a date with him because if he rapes her she can’t scream for help, so Sally doesn’t want to go on the date. She doesn’t tell this to Harry, so she just doesn’t show up.
Sally is standing someone up.
She is standing Harry up.
Harry is being stood up by Sally.