してしまいますから - meaning

[HopeIsNope]

What does one mean when saying something like message B in a scenario like this?

A: いっしょに食べに行きませんか。
B: すみません。これをコピーしてしまいますから。

Does B mean (1) “Sorry, I will only be able to go after I copy this [please wait for me]” or (2) “Sorry, I can’t because I have to copy this [go without me]”?

[heisamaniac]

てしまう can mean “do something completely” or that the verb is causing an unfortunate event. In this case, I guess it could be a mix of the two.
“Sorry, because I will copy this (completely, until it’s finished).”

Other examples:
電車の中に鞄を忘れてしまいました。
でんしゃのなかにかばんをわすれてしまいました。
I left my bag on the train. (regret/did not intend to)

授業に遅れてしまったんです。
じゅぎょうにおくれてしまったんです。
I was late for class. (regret/did not intend to)

本を読んでしまいました。
ほんをよんでしまいました。
I finished reading the book.

[HopeIsNope]

Thanks for the reply, but I understand the meaning of てしまいました already

What I don’t understand is てしまいますから (see examples I provided). Does「すみません。これをコピーしてしまいますから」mean please wait until I copy this, and then we’ll go or sorry, I have to copy this, so go without me (I will not join you) or even sorry, I have to copy this, so go without me, and I’ll join you later?

[acm2010]

Japanese is vague, so there is no real reason why it can’t be any of the options. I think it’s “go without me”, すみません is pretty strong, for the other options you would start out with the “please wait” part.

[Leebo]

I don’t see how the tense of しまう relates to the implication of being able to go or not.

[heisamaniac]

Oh, sorry I missed that.
I wouldn’t be able to say for sure but when I read it I thought that person B could not go because of the explaining and apologizing. I’m imagining that the から is implying something like…

すみません。これをコピーしてしまいますから行けません。

[HopeIsNope]

Thanks, got it!