Goby & Condy living together

[DeSimone93]

So my friend has a condy anemone, and has his two clownfish hosted by the nem, which isn't anything strange, but they also have a guest, a green clown goby. The goby sits inside the condy and neither seem to have an effect on eachother. How rare is this?:uhoh3:
http://i1289.photobucket.com/albums/b506/mariodesimone93/725e6267-066f-49e1-a6cb-f212e303be25_zps12132da3.jpg