Free for all?

So I started at a gym two weeks ago.....I checked out a few of them over the holidays...just to see which one was gonna be more pleasing to me and the cost of each of them.....as it turns out....there are quite a few more gyms I have not seen yet but I am now hearing about from others. However, while I was at one checking it out over the holidays, they gave me a three day free pass. So on the first day, I checked in at the front desk and gave them my pass card, to which she entered my info and told me that I should just give them my name when I come in and once I sign up, just let them know I am in the system already.
Well....I have yet to "check in" at the front again....I just walk in everyday, say good morning to the regulars, smile at the desk lady and proceed into the gym and work out for an hour....then as I leave an hour later say goodbye.
Sooooooooooooooooooo......now it has me VERY curious....how long can I get away with this....can I go there for a whole year and NEVER pay a dime? LOL.....STTAAAARRRTTTTT TTTHHHHEEEE CCCAARRRRRR (you know that funny Ikea commercial with the lady that comes out yelling this cause she got a good deal)
Anyways....the honest part of me thinks I should own up tomorrow and pay...but then the deviant side of me says....NAH, lets do this fun experiment and see how long I can go for free...and if in six months they still say nothing...totally call some famous news cast and tell them of this hilarious thing I pulled off lol!