How to ask my cousin if i can copy his tattoo?

So my cousin is 33 and I'm turning 18 in a few weeks and I've always know I wanted a tattoo. My cousin has a tattoo of a shield with a knights head piece and two spears underneath with rosary around it and he has the shield broken up into 4 sections one with our last names first letter (c) and one ha a cross and one has a cross , one has an amerian flag and the other is a shamrock because we are Irish and it has loyalty in a banner underneath it. I think this tattoo is so cool it represents my family who I am and I would do anything for my famil... So how do I ask him if I can copy his tattoo it's on his arm and I would get it there too... We arnt really close so what would I say