Does a video lightbox need a close button?

I am building someone a portfolio website for their videos. When you click a thumbnail in a gallery of videos, a light-box no bigger than 65% of the viewport opens to show the video. You click the dark part of the light box to close the video and go back to the gallery. The light-box does not paginate.

I'm now almost done with the site, and have started overthinking one of the UI design choices I made.

It seems intuitive to me at this point to click the dark area of the light-box to close the video and return to the gallery. As it's become a very normalized behavior, but I know I'm biased based on my own experiences.

My other argument to myself is since the video never completely covers the video gallery, and the dark part of the light-box is only at about 70% opacity, you would want to click on the videos to bring them back.

Do I need a close button? Am I taking too big of a risk for user frustration? Would love some opinions or even better, theory, as to why or why I don't need one.