Learn Spanish (Latin America): Como acabamos de terminar, cierra la boca nomás. - Since we just finished, just close your mouth.

In Latin America, placing nomás after a command softens it. Cierra la boca on its own can sound blunt or aggressive (like "shut your mouth"). Adding nomás acts as a pragmatic attenuator—it softens the delivery, making it mean something closer to "just go ahead and close your mouth" (for example, a dentist speaking to a patient).

Why do we use Como here to mean "since" instead of Porque?

In Spanish, you generally cannot start a statement with porque to give a cause or reason. To say "since" or "because" at the very beginning of a sentence, you must use Como.

Why is it la boca instead of tu boca?

In Spanish, body parts take definite articles (el, la, los, las) rather than possessive adjectives (like tu or mi). Because the command is directed at you (cierra), it is already obvious whose mouth is being closed.

What does the phrase acabamos de add to terminar?

The verb phrase acabar de followed by an infinitive means "to have just done something". So, acabamos de terminar translates to "we just finished". It is the standard way to express the immediate past in Spanish.