Have you ever met a native English speaker, speaking a foreign language fluently? What was the language and what did you feel?

Yes I met a native English speaker who spoke better Arabic than me and I felt bothered but proud of him for speaking it and taking the time to learn Arabic.  He is now my mentor and teaches me the correct and proper way to speak Arabic :)

Yes I have. in my current college, several of the lecturers speak fluent Arabic, and we are all native English speakers. 

To this question I only have to say ...

there are many talented people speaking a foreign language (or more) as well as their native language ... and accents are at times hard to detect  ...

in my case I am a native speaker in German and understand most of the languages spoken in the 16 States of Germany ... 

I understand some Dutch and Flemish because I speak German and English; some Spanish because I have some formal Italian and French language classes...

I can translate technical terms in German and English. 

Most tell me I have an Irish accent and can not believe I have no English accent in my German after living over20 years in the US.  

Yes i have.

When i was studying English at the British council in Jordan, i met an English teacher who was learning and speaking Arabic. He was good at speaking Arabic, he  fluently speaks it , i really was astonished by his intelligence.

an American speaking yoruba (african/nigeria language) and i felt amazed and proud of the language and where i came from.........

i have never met any person yet, but i think that the English language which i speak is like an office language because it has not so much common words which are used in our daily life.

yes i have

I did meet with a US citizen in Iraq who spoke Arabic language fluently however i thought he is Iraqi but once i knew  he's not Iraqi I respect this guy very much as he learned arabic just because he wants to understand the needs of Iraqi people during the Gulf war in order to help

Yes I met  Actually he's amazing because he spoken   local Cebuano language well without formal education on it. And I felt curious and try to know where he learned of such; expressing local Cebuano language (1 of the Filipino dialect in southern Philippines) with correct grammar, usage, diction, and  the reason why he strives much to in vibe it as part of his life routine. Perhaps his intention is to live like a local residents and the only way to live with them effectively is to embrace their own tongue and culture. 

I have many who speak English fluently and I enjoy talking English with them and they try to learn my slang Arabic

I MET A SAUDI ARABIC NATIONAL ABDUL KARIM AL MUSTAFA ,WHO WAS VERY GOOD SPEAKER OF ENGLISH LANGUAGE,HIS COMMAND ON GRAMMAR WAS HIS KEY SKILL ,WE WERE CASS MATES,I ALWAYS ENVIED HIM BECAUSE OF HIS STRONG GRIP ON ENGLISH.