Situation: You are with a friend and you explain to him/her that María, a mutual friend of yours, is pregnant. Your friend asks you whose baby it is. You are surprised that s/he doesn’t know, because everyone knows that the father is her boyfriend, Guillermo. Tell him/her that it’s Guillermo’s baby.
Semantic interpretation: Statement of the obvious.
Speaker: MDF
Utterance: Pues... ¡de Guillermo!
Translation: Guillermo’s [of course]!