how do you say "i miss you two" in spanish?

Los extraño. That would be i miss you, "los" implies more than one person.

If you want to add "you two", you could say "Los extraño a los dos"

If you get a tattoo that says "I miss him," when the two of you are together again it will look like you are missing someone else who is not present. Two pieces of advice: never get a tattoo to express a temporary situation that will definitely change, and never get a tattoo in a language you don't understand (there are shades of meaning that you might not want to include).

se extrano a ustedes

its actually te extrano tambien