I just wanted to report this somewhere in case it helps anyone in the future.
My husband and I decided to go to Lisbon and Porto, Portugal for our honeymoon. On our second day in Lisbon, we were walking back to our hotel near Avenida Liberdade at night around 9:30 pm, and a man began yelling racist remarks at us. My husband is Chinese American and I am white. We feel sometimes that people don’t like seeing a person of color with a white woman and that it may have drawn extra attention to us. We were walking quietly, but holding hands. He continued to yell at us, and we both told him to stop. In the future we will say nothing as I believe it made it worse. We continued walking and a minute or two later we heard a noise and realized he had followed us and thrown a rock at us. At that point we stopped to assess if he would come closer but he didn’t. We continued walking back to the hotel without incident. At no point did anyone intervene or warn us that he was coming after us. We talked to different people in Portugal and the people of color told us that there is a lot of racism, but that it usually not directed at tourists. We ultimately decided to come home early. It was a hard decision, but we felt we would be paranoid the rest of the trip. Next time we go anywhere else (and of course, there is tons of racism right here at home, but we know the laws here, and we know other people we can call for help), we may choose not to hold hands at night, and we will be more vigilant. We know other people of color who have had wonderful trips in Portugal, we were unlucky, but as I said to my husband, it doesn’t help when someone tells you “that almost never happens here!” when it has already happened to you.