I have to correct myself. According to Goblinboy it is possible to catch Jenny masturbating with the webcam. After being asked about it he said so in the aif yahoo group:
I believe you can get that one in the game, yes. I *think* you need to use the webcam and your PC to get it...
I just hope he wasn't confusing Jenny with Laura...
On Monday, day2 it doesn't matter if silvers catches you or not, I believe you can always go and screw Anna. You either bring her home or you go there on your own.
On Tuesday,day3 after catching them red handed, I tried but with no luck.
Another note: I read it's not possible to screw Nikki being stealthy. That's wrong! I haven't tried with taking a picture of her first, but if you just talk to her Mr Holiday leaves and you can do her all you want.
Funny thing is, in the end Silvers always has the picture of them screwing on the bench although I checked the park every other day as well.