There's 5 primary partners; Nathan, Kate, Violet, Matt and Damien. Violet has two routes, sub and dom. Up until the route lock for each, you can have basically all of them running at the same time, but there will be conflicts and Conflicts; you might miss some content, and eventually there's a conflict scene between the various paramours; mostly Matt vs everyone else right now. Matt also has some crossover with a side path and the both jobs, making him the default asshole to have for either job. So you have at least 6 saves for that, plus the various Conflicts between the characters, not all of which are in the game. There's also 1 scene with Matt that you have to slap him for, though you can escape it (rape warning), but isn't bound to anyone's route other than not being on Matt's and slapping him like a bitch. There's also a scene with Damien/Matt that depends on whether you save Damien or not and are on Matt's route, and of course the Conflict between Damien and Matt. Conflicts between your various paramours also vary whether you support one or the other; There Can Be Only One (*Queen plays*).
There's 3 clubs exclusive to each other, with Damien having some crossover with the Cheerleading squad (which has the most content by far). So you'd want to run Damien and Cheer at the same time. The track and photography club have very little content right now. So you can run them with pretty much any partner.
There's 2 jobs, Bakery which eventually Conflicts with Matt right now, and locks you out from Kate, and the Cafe, which gives you Kate, and splits into a corruption and pure path. There is a split whether you are corrupting Kate or not as well, and the Kate/Matt Conflict scene. The Cafe leads to the bar, which again has a couple minor splits, and some crossover with Matt and Violet. So you'll have to have at least 3 Matt saves, 2 for the Bakery with Matt, one Pure and one Corrupted, one for the Bakery, 3 for the Bakery with one Corrupt w/ Kate, one Corrupt w/o Kate, and one Pure (which will have Kate as your partner). You also want to go the Pure/dating Kate route with Matt at least once for the Conflict scene. I don't think there's a Conflict if you Corrupt Kate and are going with Matt.
Both jobs can eventually lead, with Matt and I think Violet, to a fourth job that I don't think has any real content yet, and is mostly to avoid a bad ending scenario.
There was a mod with one additional rape scene out there, but I don't think it's been updated, and wasn't part of any route. If my art wasn't so hideous, I'd dig out and finish the aborted mod I had started, and never finished, but I have to tell people Hulk Hogan is the Jabroni of the Earth, so my time is limited. Also, I'm really really terrible at art.
