Temporarily hiding a new tattoo?

So, I turn 19 in a few weeks and I m getting my first tattoo this weekend, kind of as a birthday present to myself. My mom though, she seems to have the idea that one should wait substantially longer before getting tattooed even though she and my father both were tattooed at younget ages. My tattoo will be on my forearm, just below my elbow, and I m wondering if any of you have some tips so I can hide the tattoo until a little after my birthday, just to give the impression of a longer wait period.