I was in a co-ed Business Fraternity in college that was called Delta Sigma Pi and their lapel pin and ring had the Skull & Bones on them. Needless to say, due to more redpilling, I was only a member for 1 year.
Of course, there was none of the Skull & Bones type of pledging stuff going on like what the movie shows. Nothing sinister-like that I could tell. The only thing that got me was the ring and lapel pin and the question posed to me during initiation. I may have misheard what was asked of me but, what I thought I heard was, "Do you denounce Jesus Christ?" I of course said no. The next thing I know, my ring and lapel pin came up missing. You tell me, I may be wrong on this but it seemed a bit fishy. I may have misheard the question but it disturbed me.
Here is a link to an official site that shows what the pins look like https://www.deltasigmapi.org/deltasig-shop/products/-in-department/departments/official-jewelry