Having a hard time with potty training. He will go outside and poo. But if he sees us not looking he'll go poop in another room if the gate is open

It sounds like Alexander has figured out that going indoors is something he needs to hide from you — which is actually a sign he does understand it's not ideal! That's a good foundation to build on. Five-month-old Belgian Malinois are incredibly smart and energetic, which means they can learn fast, but they also need very consistent rules to really lock in a behavior.

Here's what's generally helpful at this stage:

Tighten up supervision for now
- Until he's more reliable, treat him like he's brand new to training. Keep him in the same room as you, or use a leash attached to you (sometimes called an "umbilical" method) so he can't sneak off.
- Close gates or doors to other rooms consistently — even when you think you'll notice. Malinois are quick!

Reinforce outdoor success every single time
- The moment he finishes going outside, praise him enthusiastically and offer a small treat. The reward needs to happen right after he goes, not when he comes back inside.
- This age is prime time for that reward connection to really stick.

Watch for pre-potty signals
- Sniffing the floor, circling, or suddenly leaving the room are common signs a dog is about to go. If you catch him doing any of these, calmly redirect him outside immediately.

Don't react big to accidents indoors
- If you find a mess after the fact, quietly clean it up with an enzymatic cleaner (this breaks down the scent so he's not drawn back to the same spot). Reacting with frustration can actually make dogs more likely to sneak off and hide when they go.

Stick to a schedule
- At 5 months, most puppies need to go out every 2–3 hours, after meals, after naps, and after play. Predictable timing helps prevent accidents before they happen.

Belgian Malinois are a high-drive breed that thrive with structure and clear expectations — consistency now will pay off quickly with a dog like him.

When to see your vet: Potty training challenges are usually behavioral, but if you notice Alexander is going very frequently, straining, producing very small amounts, having loose or bloody stool, or seems uncomfortable when he goes, those are signs worth a vet visit soon — ideally within a day or two. Also make sure he's up to date on his puppy deworming and vaccines if you haven't already checked in with your vet recently, as parasites can sometimes affect bowel habits in young dogs.