Your question doesn't make sense. The texts are threaded by sender, and you can only have one sender per text. So if 555 sends you a text, when you respond it goes back to 555. There's no difference between threaded and non threaded in this respect. If Bob and Judy are both using 555 to send texts ( I don't know how that would be) then you've ALWAYS been sending back to both when you respond to 555. Threading is just organizational, it doesn't change how replies work.

 

Ok, i get what your saying. Just copy the msg txt by pressing and waiting for the popup menu to come up (doesn't this remind you of the apple and the press and hold for right click?) and in the popup select copy txt. Goto the the txt field and then hit insert txt. And then reply from there. Or you could select forward and just input the number in there for 555 and replay from there.