Referring the question to  Zienab Mostafa, a prominent Muslim Scholar and Da`iyah, she said,

Privacy in intimate relations between husband and wife is not merely in place but also, from the moral perspective, is in speech with strangers as well. Intimate relations are supposed to be practiced within the boundaries that secure honour and dignity for both husband and wife, and save them from intruders. That is why they should be practiced in a closed area where the couple enjoy this privacy and are not worried others might violate it anytime.