"We talk about moms and I obviously think of you."
Translation:Parliamo delle mamme e penso ovviamente a te.
Here it's not an indirect object, but the object of the pronoun "a." "Te" is the right form to use after pronouns.
"a" is not a pronoun - it's a preposition. So after a preposition, you use te and me?
Yup. "A" is a preposition and it is followed by "te", "me", "lui", "leit", etc.