In order to see Ryan cheating you need to keep going to the night club from when it opens up to around 2.00 or something until the event triggers
Viewing post in Love & Sex : Second Base comments
Most of the time for me it kicks off the event as
I enter but once I had to wait until it popped. Keep pressing the wait button as it will pop. I still haven't got a call from Sam to kick off an event though that you can get after her wedding. So your game might be bugged. Also i can't get a load screen only a save screen on my game. Qload only loads just one save and it is never the current one. Might need to reload my own.