Just in case, send an e-mail to them
Normally there shouldn't be any problem, but when dealing with lawyers & ip-stuff, it's always better to have correspondence and permission. Even if it is just a formality
Besides, they'll lmost definitely agree to that - this is just to make sure.
*one thing - If there's still time, specify that you want to get this tattoo for yourselves, not add it to your design palette as a tattoo artist - because that last one could be potentially troublesome.