KJ and TS were spotted with young Stormi Sunday at Sky High Sports in Woodland Hills -- which is a giant trampoline warehouse. As you can see, it was just the three of them here (plus at least one bodyguard trailing behind) ... and the parents got pretty close.
It looks like Kylie might've even attempted to take a selfie of the trio while they were walking in. BTW, eyewitnesses tell us they didn't rent the place out -- the family just rolled up like regular customers, although they did bounce around in a VIP area.
In any case, it's clear they're not averse to one another ... which we'd heard was the case at Stormi's recent birthday party. Remember, sources told us the former couple were hanging out pretty much through the whole party and gave off signs of a possible rekindling.
Anyway, later on Sunday ... they hit up a nearby mall and plaza where we're told they stopped off for frozen treats at Afters (great ice cream spot out there). At this point, you could definitely make out one security guard who was rolling with them, but again ... pretty intimate setting.
If they aren't meant to be together romantically, it's at least comforting to know they can get together and co-parent their child successfully. Good on them.