He is accused of a lot more than flashing. The "lighter" of the allegations are things such as him quickly moving his body so that they have to touch his manhood but that is not all the allegations. Just for a couple of the more serious allegations one women who alleges that he forcibly groped her um lower half during the massage (front and back), some allege forced oral sex, and one that alleges he started pleasuring himself during said massage and then after the masseuse understandably stopped massaging him he stood up and continued until he finished on her.
The lawyer for Watson seems to be taking the position, note this is still illegal but less so than the allegations, that these were just massages with standard happy endings which based on the way the reported deposition went also seems to be the case. Specifically where he admitted that the women he was seeking out, he did not care about their experience or skill level or training because "that wasn't a priority". So the defense seems to be arguing that all the allegations were consensual which as an aside is probably not the smartest move for a civil case.