In all languages there are familiar ways to refer to “father” and “mother”. In Spanish, we have papá for padre and mamá for madre, just the same way we have “dad(dy)” for “father” and “mom(my)” for “mother” in English.
The thing is, in Spain, the use of papá and mamá is much more restricted than that of “mom” and “dad”. Note that I said “in Spain”, not “in Spanish”, since in Latin American it’s more similar to English usage.
I don’t think there are exact guidelines, but many times the use of papá and mamá will sound really weird, so you better avoid it unless you are sure you are using it right. Here are two basic rules.
Don’t use them unless everyone is part of the family
In English it’s perfectly normal for someone to say to a friend something like:
But note that in Spain you have to say padre and madre, because if someone isn’t part of the family, it will sound weird.
In the first example, the speaker belongs to the family, but the hearer doesn’t. In the second example, it’s the other way around. So in both examples padre and madre are required.
In this example, papá is fine because the subject is speaking to a relative (the mother, the brother, the sister, etc.)
I would say that this “rule” is so strong that it shows how close the speaker considers the relative he is talking to. If the speaker considers the relative close, he will use papá or mamá, but if he considers the relative not so close, he may use padre or madre.
Don’t use them if there is a possessive
This rule coexists with the above rule. Most of the times, when someone in the conversation doesn’t belong to the family, the use of a possessive will be required. So, this other rule states that you shouldn’t say papá or mamá if you are using a possessive (or some word denoting possession).
And never, ever say papi and mami!
In Spanish we also have papi and mami, but don’t ever use them. Only very young children can use them…
Because if you aren’t a very young kid, that means that you are into some kinky roleplay.
The reason for this might be that some Latin American countries do use papi and mami when talking to their boyfriend or girlfriend. As racist as it may seem, the use of papi and mami reminds of Latino prostitutes trying to win over a customer.