“Just chill” won’t work with people that have never met and can’t communicate
You will need to
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Get your partner to commit to learning your language (“failing” only happens when you stop trying)
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Get your parents to commit to learning english
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Plan the shit out of the next visits so there’s plenty of activities to share and not just awkwardly being around each other
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Think about moving in together somewhere with an extra room that can be prepared for your parents for 2 weeks out of the year and other visitors or activities during the rest of the year (ie home office media room home gym guest room, whatever)
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Just get them an airbnb nearby for 2 weeks. Spend the days doing activities in 3. and then everyone goes to bed in their own place
My advice would be to try to reach retirement age in europe before moving to south america, then take advantage of pension in euros vs cost of living in local currency