Is It True That a Nigerian Married To A Foreigner Will End Up Marrying Another From His Tribe

I lost my two kids a few months ago. Days after, my marriage crushed. My hubby couldn’t handle the whole thing so he filed for a divorce. Few weeks after that, I also lost my mom. During this whole dilemma, I met a man on MIM Facebook who was there for me. He did everything possible to get my remaining child who was also sick live.
He stood by me when all hope was lost. A total stranger who showed me love, gave me a listening ear and gave me a shoulder to cry on. This man proved himself to be faithful and honest. Even when I was so down and needed someone to take care of my businesses, he was there and made sure that all of them were up and running as they should. Not that he had nothing doing. He has his own business. He just has a big heart.
Ever since I met him, my businesses have grown bigger and I’ve opened new branches. This is a man who encourages me to be the best I can be and respects me a lot.
We’ve grown to fall inlove with each other. He’s introduced me to his family and they all seemed nice. The issue is that he’s from Nigeria and I’m not. I’ve heard people say that a Nigerian man married to a foreigner, doesn’t matter how nice his people are, in the future, they will insist he marries another from his tribe. He tells me he does not come from such a family and will never allow that to happen but I’m scared and a bit reluctant to go ahead with the relationship because I don’t want to be a victim of this practice. Please tell me, is this practice happening for real or it’s just a rumour?

Would you advice I go ahead and marry this man anyways, if I were your sister? Please advice. Thank you all.