If she doesn't know that you're talking to other women or looking for another wife then its cheating and low down. Tell her about it. The afar ba la ii baneyey somali males always sneak around like little kids who know their doing something wrong. Creating whole families that don't know about eachother and when the first wife confronts him they gaslight saying "well you would've left/wouldn't let me if I told you".
A first wife has rights and it's her decision if she wants to share her husband or not. I've even heard somali men abusing their wives into agreeing to a second wife or kicking her and their kids out on the streets when she refuses or infecting their wife with STDs and HIV.
A wife has every right to feel secure in her marriage and once the lies and sneaking around comes in it's the end. Communicate instead of leaving her in the dark. If she's ok with it cool if she's not also cool, qhasab iyo xog ma jiro.