Back when I lived in the United States, I dated a lovely woman of Dominican descent who was equally fluent in English and Spanish.
She had one habit that irked me at the time: when speaking English, she would often pronounce words of Spanish language origin, such as burrito, with a Spanish accent. A silly thing to be bothered by, for sure, but for me it seemed just a bit elitist, as if she were demonstrating that she knew how to pronounce a word better than everyone else.
I would point out that burrito was is in fact an English word. It exists in English dictionaries, complete with an English pronunciation.
I would point out that the English language is full of these borrowed words. Should we pronounce all words using the accent of their original language? Should we pronounce résumé with a French accent and kindergarten with a German accent? One could easily switch accents five times in a single sentence, and I don’t imagine anyone would consider that a good idea.
This question of pronunciation has resurfaced in my life, this time from the other direction. Now I live in Argentina, and here there are a handful of English words used in every-day life. For example, shopping means mall. Yes, in Argentina, the word shopping is a noun. It is used as in “They went to the shopping.”
And I must admit: now I understand why my girlfriend was so against pronunouncing burrito in an English accent. It is hard to butcher words from your own language! It really feels funny.
And, ironically, these borrowed words are among the hardest for me to pronounce correctly in Spanish. While real Spanish is beautifully consistent in its pronunciation (if you read a word you can pronounce it, and if you hear a word you can spell it), these borrowed words are not at all consistent. They are typically pronounced about half way between English and Spanish accents.