My wife is American, we dated for almost 2 years across the atlantic with a monthly visit no problem whatsoever. And yes, this was after 9/11. And yes, I told them who I was visiting and why, I always figure a single lie is enough reason to put me on the next plane home.

In my experience, the key factors were that I had a mortgage and a stable job i.e. a reason to go home at the end of the stated period (usually a 5 day weekend). Going for shorter trips was easier than longer ones as 4/5 days isn't long enough to get over the jetlag let alone look for a job. Show as much intent as possible to return home. I also once told a ICE guy that I was a law abiding citizen and that if I planned to stay I would do it legally.

Once you've done the trip a few times, they worry less as experience shows that if you say you're going to leave, you will. Best of luck with this and enjoy yourself, it really is quite a lot of fun!