Christians: What are you Hiding?

I was struck recently by some of the passages of scripture I was reading, that we as Christians probably "hide" a lot of our behavior, habits and activities from others, but we can't hide them from God.
This of course brings us into the "what's moral for you is not moral for me" argument, but I am challenged to think, "will it cause my brother" or perhaps a non-believer who looks up to me (for whatever reason) to miss seeing the Cross due to my behavior?
The easy ones are drinking, smoking, overeating, but what "hidden" things might there be?
Now I am not calling out any of these things as "sin". I am looking for discussion on how does our behavior, habits or activities, might be construed as "immoral" to our brothers and sisters in Christ, as well as those who KNOW we call ourselves Christians, yet they might be confused by our outward appearance.
This is a discussion post today, so, DISCUSS!