NBA stars Ben Simmons and Tristan Thompson hit up the Lamborghini dealership in Beverly Hills recently ... and it just goes to show that even though they're no longer with the Kardashians, they still got time for each other.

Of course, TT and Khloe went through a nasty breakup after the whole Jordyn Woods drama ... and Kendall Jenner and BS just cut things off for good last month.

But, these guys were bros way before dating KarJenners ... they're both Klutch athletes and have been hanging out in the same circles for years.

We're told the duo looked at cars for about an hour before driving off in Ben's Ferrari ... so it's unclear if they found anything they liked.

After all ... the dude REALLY loves Ferraris.