Guys, What is the kindest reply I could give this guy?

So a guy I had spoken one sentence to before, to let him know I don't speak his language well... he suddenly hearted me after I changed my profile picture. I hearted him back.

.. I just saw that the guy sent me his whatsapp number. Just sent it without saying anything ( raise eyebrow )

... I hearted him as a compliment...

Is it kinder to just say nothing, leave the message on read... or is it better to say " You have a lovely profile and that he is handsome but ___________"?
Guys, What is the kindest reply I could give this guy?
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