He is best known for his monumental El Beso (the kiss), a large sculpture unveiled in 1993 in the "Love Park" by the Pacific Ocean in the Miraflores district of Lima.

"[1] Delfín was the youngest child of eight in a poor family of a welder in Lobitos, a coastal fishing village in the Piura region of northwest Peru, and grew up watching and helping his father grind bits for oil rigs in his workshop.

"One of the main distinguishing features of Delfín's work is that in the context of experimentalism, which at the time was mainly focused on art styles, systems and institutions and would lead to a crisis of representation and an ensuing widening of the material possibilities of production in plastic arts, Delfín also took it upon himself to ensure the continuity of a creative current socially subordinated to the current proclaimed as 'art' by modernist idealism.

"[7] Delfín helped organize writers and authors in opposition to Fujimori and in 1995 participated in the Caucus for Peace, which brought together artists to protest the threat of conflict between Peru and Ecuador.

In 2000, Delfín addressed young Peruvians in an open letter, encouraging their protests but warning "of a looming struggle against the dictator retaking power.