Asking about an interpersonal action is directly on-topic at this website, and mentioning which culture you are referring to is equally on-topic because it supplies the context that is vital to answer the question.
'Is behavior A acceptable' is too generalised a question, so it is necessary to add 'in culture B' in order to achieve the specificity that keeps the question on-topic (and the fact that such a question has a factual basis makes it even more on-topic, as suggested in the earlier answer) according to the core principles of Stack Exchange!
However, as elsewhere in the network, and as hinted at in the earlier answer, the person asking such a question should supply adequate references to justify their connecting behavior A with culture B convincingly enough to make it a relevant question.
Example: is eating meat acceptable in Sweden? It is not acceptable among many communities in India.
Unless the asker could convincingly link the 2 statements with references, I wonder if many members would consider this a relevant question in context?