Idea is based on modification of Borromean Rings (three rings arranged so that configuration cannot be taken apart without breaking one of them). In my version, one of three rings is twisted into shape of the infinity sign. Last picture shows it in 3 different colors. It symbols unbreakable, eternal, infinite connection of two. 3D printed using FDM technique in ABS material and then polished with acetone vapor.
I also created a variant without two circles from infinity sign twisted in other way.