One of my favorites are the chains between Spanish and Portuguese:

• Garbage in Spanish is Basura
• But Vassoura in Portuguese means broom
• But in Spanish broom is said Escova
• Which in Portuguese means brush

Or

• Tea cup in Spanish is Taza
• A Taça in Portuguese is a wine cup
• But in Spanish wine cup is a Copa
• And in Portuguese a Copo is a regular glass
• But in Spanish regular glasses are called Vaso
• Which in Portuguese means vase.

Or

• Cutlery in Portuguese is Talher
• But Taller in Spanish is a workshop
• Which in Portuguese is Oficina
• Which in Spanish means office
• But in Portuguese you say Escritorio
• Which in Spanish means desk

Or a short one:

• Your last name in Portuguese is your Sobrenome
• But in Spanish Sobrenombre is your nickname
• While in Portuguese nickname is Apelido
• But in Spanish Apellido means last name

Another one I like is Vamos a chatear 1 rato which in Spanish means “let’s chat for a little while” but in Portuguese means “let’s bother a mouse”.