I've been looking for for a long time

[herbivorie]

I finally found the address of my former teacher that I've been looking for for a long time. I hope she still lives there.

In the above sentence, is it correct to say "looking for for a long time"?
There are two "for"s and I'm not sure if it's correct, although I think they are both necessary because they are "looking for" and "for a long time".

 

[bhaisahab]

I finally found the address of my former teacher that I've been looking for for a long time. I hope she still lives there.

In the above sentence, is it correct to say "looking for for a long time"?
There are two "for"s and I'm not sure if it's correct, although I think they are both necessary because they are "looking for" and "for a long time".

It's fine.

 

[Tdol]

You could rewrite it to avoid having them so close together:
I finally found the address of my former teacher. I'd been been looking for it for a long time.