STEP BY STEP 英語表現1092

behind someone’s back

（人）の背後［陰・いない所］で、（人）の目が届かない所で、（人）に隠れて、（人）に内緒で（こっそりと）、（人）のいないときに、（人）に見られないようにひそかに

Janice: Okay, you know, one of two things is happening here. Either you’re seeing somebody behind my back, which would make you the biggest jerk on the planet, or else, you’re pretending that you’re seeing somebody which just makes you so pathetic I could start crying right here in the cereal aisle. So, which of these two guys do you want to be?

– “FRIENDS” Season 3 Episode 04

Joey: Who?
Chandler: It’s me. I’m the other guy.
Joey: What?
Chandler: Yeah, I mean when you were late last night, Kathy and I got to talking, and one thing to another and…
Joey: And what?! Did you sleep with her?!
Chandler: No! No! No! I just kissed her.
Joey: What?!! That’s even worse!!
Chandler: How is that worse?!
Joey: I don’t know! But it’s the same!
Chandler: Look, I’m sorry! But there’s nothing I can do, I think I’m in love with her!
Joey: Who cares?! You went behind my back! I would never do that to you!
Chandler: You’re right, I have no excuses! I was totally over the line.
Joey: Over the line?! You-you’re-you’re so far past the line, that you-you can’t even see the line! The line is a dot to you!

– “FRIENDS” Season 4 Episode 07

*over the line  度を越した、言い過ぎた、やり過ぎた