Best thing to do is see a dentist!
Teeth do move as you get older, generally but not always it’s from the back towards the front ( it’s called mesial drift ) so it’s possible that’s the reason.
However, if you have gum disease ( not gum recession as that’s not the same thing ) it means that the ligament that holds your teeth in the jaw is being destroyed and while this is often a symptomless process, teeth drifting around can be a sign. You need to rule this out as ultimately it can lead to multiple teeth being lost.
Finally you could have a small hole in between in one or both of those teeth. It wouldn’t necessarily be visible to the layman’s naked eye. Again a dentist can check this visually and with an x- ray.
The remedy depends on the cause and runs from you just have to put up with it and keep it clean to filling, or a cap/ crown to you need your gum disease sorting out.
Like I said, get a check up!