I had an interesting discussion with some friends recently. We were talking about some offensive words in particular language and how meaningless they can be in other languages. For example, in French Quebecers, Tabarnac, literally meaning “tabernacle”, a cupboard for the Blessed Sacrament in the Catholic church (I think), is a curse word. Quebecers used to be very religious people and ,therefore, the religious words are taboo and if they are used, it considered swearing. There are so many similar examples like this in French (Canadian version). Now, try to apply this in Farsi. As one of my friend suggested, if you call someone amameh, meaning turban, it is not only offensive but funny.
On a slightly different note, when you are trying to be affectionate, the language that you are most comfortable with always rules. I know of a young couple; the woman is Mexican and the man is from Quebec. When they first met, they always spoke Spanish. Now that the woman is fluent in French, Spanish is still the romantic language in their home. She told me they even tried to speak French couple of times but 'I love you' in French, Je t'aime, is not the same as 'te amo', in Spanish.