I'll be travelling to Malaysia from Thailand in a few weeks. I have two EU passports issued by the same country, both of which are valid, and I want to enter Malaysia on my B passport. The reason for this is to keep the stamps from certain hostile countries apart in different passports (Malaysia vs. Israel, Azerbaijan vs Armenia etc.).

I've heard stories about border officers being flabbergasted seeing multiple passports from the same country because compared to multiple passports from different countries, it's less common.

I might need to show them my A passport in case they look for the exit stamp from Thailand in my B passport. I heard that happens sometimes.

The last thing you want is surprise a border officer. The first surprise would be no Thai exit stamp, the second would be the two passports thing. I know what I want to do is legal but the thought of having to explain myself to immigration freaks me out. If they ask me why I'm changing passports I can't say it's because I want to hide you from a country you don't even recognize. I just want to go through immigration smoothly.

Does anyone have any experience related to this?