It all depends on what kind of hash you get.I have smoked half a dozen different types of hash and the softer it is, the better it is as a general rule.The really hard hashes usually have too much fillers and binders for my taste.
And if it is good hash, you may indeed have trouble looking straight for mom and dad.They may mistakenly think you are on opiates though, since I find hash to be more sedating and pain relieving than weed.But hash smells similar to weed, so if they know what weed smells like they will likely recognize the smell of hash as well.