How transparent are you with people at your "day job" about REI?

[Michael C.]

So, I just finished listening to Podcast 60 with @SergeS and it got me thinking.  He was working a full time job, and took his business from 0 to 68 units in four years.  In the podcast he referenced very often he would be in meetings, etc and his phone would be blowing up with his "other" job.

What I was wondering is, for people like myself who are just starting out, but keeping our day job, how transparent should I be (or not) with my current company/boss about what I'm doing?  I have to imagine it will illicit a number of questions if my phone is blowing up all the time, or what if someone finds my company website (when I actually have one).  But clearly a double edged sword about explaining why you are starting to invest/building a business.  My inclination is to not mention anything, but didn't know what others experiences have been.  Appreciate the thoughts of anyone who has done it.

Mike