I know that works for the mum path, I already finished that one

What I wanted was go to the party with EVA and without mum, but Des keeps showing up to the party too despite me treating her badly on purpose, and then when the argument between Eva and Des happens, it doesn't matter what you choose, it ALWAYS ends up with Viv and Des making out and then having sex and then acting like they're suddenly in love. And this after I've been telling Eva aaall this time I want something more with her while treating Des like shit.
The only way to completely avoid Des is sleeping with Rebecca, but I also don't want that cause it turns out Eva ends up noticing you did and she seems hurt