How can I not miss the path with Lauren after the massage scene?
Same, you need 9 or more points with her at that point. If you win the game vs Tom at the party, it gives you +2
But I have ten points but I've always been lost.
Why don't you use the walkthrough
To win, you have to make friends with the right person at the party, then pay attention to that friend during the scene. If you don't use the walkthrough, I can only assume you want to avoid spoilers, so that's all I'll say.
