Jenelle Evans says she's not back together with David Eason, but they're still doing a lot together ... like buying new pet supplies, including a dog bed.

The former 'Teen Mom' star was spotted Tuesday shopping at a Walmart in Leland, NC -- where she was leaving the big box store with whom we're told was none other than her baby daddy, DE, and a couple of her kids tagging along. As you can see, they had their hands full.

One of the kids is holding what appears to be a doggy bed or pet bed of some kind. We're also told by eyewitnesses, their bags had dog food inside as well.

In case we have to remind you ... David killed their last family dog, which led to their kids being temporarily taken away. Since then, they've gotten the kids back ... and they've also welcomed a few new animals into their lives, including at least 2 dogs and a goat.

It's unclear if they still got the hounds running around the yard, or what these supplies might be for exactly ... but when ya buy new dog stuff, you probably have a new dog around.

As for whether they're actually a thing again in the wake of their split, we'll let you decide. If it looks like a relationship and walks like a relationship, it's probably ... ah, you get it.