Read an article on client privacy in spas just the other day. It said using photos without consent can lead to big legal problems. Free marketing is good, but not if it breaks trust with customers. Your partner should really ask first, it's basic respect. How do they react when you bring up the privacy concern?
The legal risk from photos without consent is real. One upset client can hurt your spa's name quickly. What does your partner say when you talk about possible lawsuits?