Oh, I think they've got each other wrapped around their respective fingers. I don't think she's any more irritating or manipulative than he is - notice how this week when she had to come up with a big number to save face his weight loss was pretty low? They're both playing the game. I'll do the why first - it's hard to keep pulling big numbers week after week, so if a team has immunity, the strategy is to somehow take it easy/lose less weight that week because you're not in danger of going home. The idea is that the following week, when a team needs to stay above the yellow line, they can manage a more dramatic weight loss. The how - most of what I've heard has been water loading - making sure to go into the weigh-in having drunk a ton of water to inflate one's weigh-in. One can also slack off during the week, but that's way more obvious and clearly hard to do around Jillian and Bob. I'm sure someone could also be scarfing down everything in the kitchen and we're just not getting shown the footage, but I think that would be harder to shake off the following week.