Boyfriends getting my named tattoo! advice!!?

We been together for going on 4 years and today I was messing with him about getting my initials. Well he was like sure, I thought he was playing and now texted me and said he just set a appointment for about a hour and is getting me and our sons name. Now I'm like I feel bad because I don't plan on us ever breaking up but still anything could happen. I know he already has a lot of tattoos but still . ADVICE PLEASE