The bully route has one issue I found rather glaring, which is that it seems to involve the MC cheating on his wife with no regards or remorse. I mean, it's one thing that he's playing games with Bob's wife, since they're into that anyway, but for the MC to turn a 180 and basically abandon the idea of reigniting the relationship with his wife takes him straight from "bully" to "asshole" -- I'm not sure who that's for.
If the idea is to have the MC's wife out of the picture for most of the story anyway, you may as well have them either split up before the cruise if the MC decides to play the field, or have his wife give them full blessing to play around with the other pair (seems improbable she'd just allow that right away, but hey, this is a porn game, so whatever). Having the MC clown around with another guy's wife while he basically doesn't know if his own one is even still alive is not just really harsh but also inconsistent with the setup.
I'd also caution the author against overcommitting, since you're basically writing two almost entirely separate games where there's not likely to be much overlap in the audiences or the content (besides the initial setup and characters). Keeping up both paths without disappointing either side is going to be a challenge. Explicitly splitting it up (if the paths are not going to overlap, which I think they won't) might be better in terms of managing expectations and pacing, since you're not forced to grow both at the same time -- just a thought.