Virtually every Indian man I know has told me that for a foreign man in his own country to say this to an Indian lady will usually be interpreted as flirting. On the other hand, one Indian lady has encouraged me to say it. However, she pointedly did not dismiss the possibility that she indeed regards it as flirting and simply appreciates being flirted with. It's strictly informal here. However, we Americans are a compulsively informal people so you may hear us say it to strangers.