After he finished, he laid Olympios by the hot tup and performed oral sex on her.
The crew member notes that Jackson had to hold Olympios up to keep her from going under the water, but that while he was doing so it looked like he was having sex with her.
Both contestants had more than their share of alcohol, but it was Olympios who was, apparently, so intoxicated that she kept going limp once she and Jackson were together in the hot tub.
According to the source, the first day of shooting for Bachelor in Paradise saw Jackson and Olympios find out that part of the storyline for the show was supposed to involve them hooking up, so the two decided to get to know one another, alone, over drinks.