What you describe has been for me a sort of non verbal checking. Am I receptive to more than a massage? This often happens when there is a language barrier. If I gently push back and they don't pull away that's the first stage. Then there's the second touch.....rubbing their groin on your hand or elbow, letting your hand accidentally brush their breast or placing your hand on their inner thigh while they massage your arm. At this point some polite reciprocity seals the deal.
Now this is not gospel. I have seen a lady at a legit spa who will do the above, and also massage my ass while she massages my low back and legs. On the flip I am at full mast. She does nothing about my condition. This is part of her game; excellent firm massage, teasing and blue balls.