Been there. But lies cut both ways. Once a company is dishonest with you, it is 100% fair game for you to be dishonest with them:
- Side consulting gigs
- During work consulting gigs, especially if you have "unlimited vacation"
- Sneaking off during the day to do whatever
That said, that isn't healthy for either party. The best situation is where both sides are honest and both sides work their hardest to reach a shared goal.