In the context of marrying a Mexican, there is no specific rule or obligation that requires a person to change their last name. Whether to adopt your spouse's last name or not is a matter of personal choice and preference, and there is no right or wrong answer. Some factors that individuals might consider when making this decision include:
1. Personal Identity: Some individuals place a strong value on their own name and identity and may prefer to keep their original last name.
2. Cultural and Familial Considerations: In some cultures or families, there might be expectations or preferences related to name changes after marriage.
3. Ease of Use and Convenience: Some individuals may opt to change their last name for practical reasons, such as simplifying legal matters, professional paperwork, and travel.
4. Symbolism and Unity: For some couples, changing last names might symbolize their union and sense of belonging as a family.
Ultimately, the choice of whether or not to change one's last name is a personal decision, and there is no prescribed rule or expectation that applies specifically to marrying a Mexican. It's important for couples to discuss their preferences and come to a mutual agreement that reflects their individual values, cultural backgrounds, and personal choices.