Try this approach. Find a relaxing time to strike up a easy going conversation, not a debate, about romance. Ask your partner to share their definition of romance. Follow this up by asking for specific activities that they feel are romantic. Once this is done, stifle any desire to debate. Remember romance varies from person to person. Respectfully accept what was said as "their" definition of romance and kindly allow the conversation to progress naturally. Next, after a few days, weeks or months, pick one of their romantic activities and surprise them by doing it. Here is a key point to remember, you must commit fully to the activity. Again, don't debate. If your partner senses any reluctance on your part to participate in the activity the moment is tainted and back to square one for you. This means it will take some self-control and sacrifice but if you succeed you will be pleasantly surprised with the result.
