That is likely the best way to do it! I haven't heard of anyone else doing that though, at least consistently.
I think because we choose to engage with each other through the use of social media, it does more to bring us closer together since it isn't just mindless scrolling. We are sharing. We are learning. We are interacting.
When I met my wife, we would spend hours chatting through FB Messenger - living together though, it doesn't happen. Perhaps we should start it up again similar to what you are doing, as it can be more playful. Might help.
I love using FB msgr, it is my preferred messaging app, but that is another story. We actually both use Snapchat and we enjoy keeping a daily communication streak alive. So even though we live with each other, we also make a point to send a funny/cute picture message to the other person at least once a day. Like you said, it is fun and playful, so we enjoy interacting like that.