Guys, or girls lol- What should i say back to this text? Pleas help :)?

I havent seen my boyfriend in a week cuz ive been out of town. We were texting n he said he missed me n i said.. i miss u way more! And he said this... Your just gonna have to prove that cause i dont think you do :) .... What should i say back? Lol i want it to be cute but argumental