I didn't snoop and I did stare at him naked. I got Carlos to come out on Oct 6th without him hitting on me. After he came out, I tried spending as much time with Adam as possible. I'm still very confused
Are you playing in the easy or in the normal mode? In the normal mode is MUCH harder to get Adam's route, I've tried it myself a couple of times and I didn't manage to get it, but using the easy mode and following the tips above I got his ending in my 2nd run. So try to play in the easy mode if you haven't already done it :P