2. When in doubt, err on the conservative side.
If there's any question as to whether you're showing too much skin—whether it's cleavage or a naked elbow or a tattoo—cover it up, even if it goes against your personal fashion taste. This goes double if you know that his family, or members of it, are unreasonably conservative.
"But I have to be myself!" Is it worth the risking an hour lecture from his grandfather on how your tattoo is the marking of the devil? Be yourself the other 364 days a year.
[Photo via @smilerinnina1994]