Does being sceptical of mixed-race relationships automatically make you racist?

First of all, lest anyone misinterpret the headline of this thread, I am not against mixed-race relationships. I believe people should be allowed to date whoever they want, as long both parties are consenting adults, and I myself would not be adverse to dating someone of a different ethnicity, as I have done in the past (albeit briefly).

However, when it comes to two people of different ethnicities dating or marrying, I cannot help but feel less confident about the survival of their relationship than if both were of the same ethnic background. I dare not say this to anyone but my closest friends, for fear of being branded a racist.

But why is it racist to be sceptical of mixed-race relationships? They have a much higher divorce rate in racially-mixed countries like the United States than marriages between people of the same background.

An academic article, visible here, by Professor Jenifer Bratter (who is herself of mixed-background) and Professor Rosalind King, entitled "But Will It Last?": Duration of Interracial Unions Compared to Similar Race Relationships", included in Volume 57, Issue 2 of the publication Family Relations, states that White Wife/Black Husband marriages have twice the divorce rate as White Wife/White Husband marriages.

As I say, I'm not against mixed-race relationships, I don't think we should have anti-miscegenation laws, as they had in the state of Virginia until 1967, or in South Africa under apartheid. However, if a close friend or relative happened to date someone of a different ethnicity, I would probably be slightly apprehensive about it.

I also do not believe that children whose parents are separated are as likely to have a happy, prosperous childhood as children raised with married parents. That does not mean I am against divorce, just that I find divorce especially saddening when children are involved.