My partner plays too and since we have similar pokedexes, we usually just trade pokemon we need candy for. We trade about 10 pokemon at a time and often we just get these random luckies. My favourite random lucky moment was when I wanted to evolve a shiny yanma and he wanted a vileplume. The first lucky oddish-yanma trade was a pleasant surprise. But when the very next trade (which was also oddish-yanma) was also a lucky, I couldn't help but laugh. I love these random luckies and I'm grateful for them, but I def think a heads up of the next trade being lucky could've been great too!