Formal:
* मला तुझी आठवण येते. (Mala tujhi aathvan yete.) - This is the most formal way to say it, literally meaning "I remember you."
Informal:
* मला तुझी खूप आठवण येते. (Mala tujhi khup aathvan yete.) - This adds "khup" (very) to emphasize the missing.
* मी तुला खूप मिस करतो. (Mi tula khup miss karto.) - This is a more direct translation of "I miss you," using the verb "miss."
* तुझ्याशिवाय माझ्या दिवसाला रंग नाही. (Tujhyashivaya majhya divasala rang nahi.) - This translates to "My day has no color without you," expressing how they brighten your life.
Affectionate:
* तुझ्या आठवणींनी माझे मन भरले आहे. (Tujhya aathvaniini maze man bharle ahe.) - This means "My heart is filled with your memories."
* तुला भेटायला मला वाटते. (Tula bhetalyaala mala vate.) - This means "I want to see you."
Remember to choose the expression that best suits your relationship with the boy.