@Michael Loucks
"Once you go black, you never go back"
Not just directed at White Women. I have heard it directed at Asians, and most other women too. (Even used on Black Women.)
I don't believe it is "racism" but it is a Trope.
It is also used as a "Pick-Up Line" (and more successfully than I would have thought).
I suppose it would come down to how you use the line/trope; if it would be perceived as racist. At least perceived as racist by rational people. It is not worth bothering about irrational people.
A particularly well-done use of this line (or something very similar) was near the middle of the movie "Full Metal Jacket" as part of the banter between some Marines. It was showing not telling one of the more common manner that soldiers and athletes "take the piss" out of each other (as our Friends across the Pond, say). Juvenile? Yes. Are some people offended? Certainly. But pretending such words aren't used is foolish.
In the movie it is an important line. Racial issues were very serious back in the USA. Marines, soldiers, and others, were aware of those tensions, but to have a better chance of staying alive, they (mostly) ignored it. Were the Characters in the movie supposed to believe the trope? They were young Marines, between 19 and 22, so, some of them might. (So too might supposedly mature people.) In the movie the hazing and joshing was part of the camaraderie. Later in the movie the same characters that had been tossing racial banter and other barbs about freely, risk their lives; in some cases, died protecting, or trying to protect Marines of various races.
I believe these issues are important to the movie. No matter the words, and even "Hurtful Intent" of some of those words. Actions count far more. People who focus on word, and disregard actions are not "helping" and are actually contributing to making racial (and other) tensions worse!
In the movie the trope: "Once you go black, you never go back" is used for humor. While I don't agree with some of the things you post awnlee jawling, I am confident you are capable of using this trope in a humorous manner in a story.