What talking you?
There is NO way you can find out for yourself whether a guy asks
for sexual favours in massage parlours by accompanying him there.
Like I mentioned, such places do not admit female customers.
Even if they did admit female customers, would the guy still
proceed and ask for extra services with his girlfriend beside him?
Geez.
WRT trusting each other, it goes both ways. The moment the guy
discovers that his girl is spying on him, that's it.
At times, ignorance is bliss. Why do many women insist on finding
out the truth, only to be devastated by it? Asking questions like
"do you still think of your ex?", "who do you find more pretty - me
or her?" is akin to shooting yourself in the foot.