Kourtney Kardashian, Kylie Jenner ... Lone Wolves on Friday Night

Kourtney Kardashian made clear what TMZ has been telling you .... she's available.

Kourtney was out at The Nice Guy Friday with no Scott Disick in sight. As we reported, she's not getting back with Scott, although they're spending time together as parents of 3 kids.

She left the club late Friday night and made a beeline for the Montage in Bev Hills where Justin Bieber stays -- he was at the club as well. She left the hotel at 4 AM.

Her sister Kylie was hanging at Saks Fifth Ave Friday night ... sans Tyga. Although it seems weird, they're still together but often hang separately so as not to confuse their brands.