Buy a cheap compass (think eBay, thrift stores etc.) and give it to your sweetheart with a note that says, “you’ll never lose me.” Or pick up a small watch or alarm clock, and attach a note that says, “no matter what, I will always have time (or make time) for you.” The compass and watch are both pocket size and can easily be carried as a reminder of the sentiment. The alarm clock can be a great reminder of your message to your partner every day as they wake to it.
You don’t have to buy the items, instead you could put a post-it note on a clock or several clocks around their house. Or text them a picture with an image found on a search engine and relay the sentiments that way.