Numbing cream

Hello boys and girls. Yesterday Monday 6 of January I made lines on my leg for 2 words, which hurt like hell. My tattoo artist says when we go again 13 of January it’s to early to put on numbing cream because it may have some side effects he’s seen one time. Do anyone of you have any experience with putting numbing cream on a place you were tattooing 7 days before. I don’t understand how that should be a problem when you only made all the lines the week before, and 7 days is a lot of time to heal for it. Please help me with advice, I am doing a full leg sleeve, and he can only visit the country once a year.