Here is a part of a conversation between two young guys:
A: わすれやしませんが こんどばかりはいくらおじょうさまの命令でもゆるすわけにはいかねえっ
B: へへっ かっこいいせりふをはきゃあがって....
I think はきゃあがって would come from 「吐ければ」which means 'If you express...' and 「上がって」 which means 'you speak out loud'.
Please tell me what meaning of this phrase really is.
「はきゃあがって」＝「はきやがって」
The former is a very slangy, vulgar, tough guy's version of the latter. (Even the latter is already fairly vulgar.)
「はきやがって」＝「吐{は}く + やがる (in て-form)」
「セリフをはく」= "to utter a line"
「やがる」 is an auxiliary verb of contempt and hatred.
「かっこいいせりふをはきゃあがって・・」
thus means:
"You just utterd a cool line!" or
"That's a cool line you're speaking! "
"Hey, you're talkin' cool, mother****!" would be the actual nuance of it, TBH.
