You dont seem to get it. The word storyLINE already implies it takes some time to reach its peak.
In the private storyline i didnt had to see any other dicks so far...okay, the fantasy of the disgusting boss, but nothing with the girls in the game. However, there are a few lesbians and i can only have them for myself yet. From my point of view there is not a single storyline far enough to include the gf yet, except for her own (the toys and the annoyingly unavoidable anal shit).
The sharing storyline had its debut on the day of your move, the cheating storyline should come later, you dont move in with someone if you want to cheat right away and she is not the possessed one.