Not sure what to do here

so me and my ex broke up a few months ago he didnt take it very well but I knew it was the right thing for me to do. During our almost 3 year relationship I obtained quite a bit of his stuff; clothes, books, a few electronics,his tassel from graduation among other things as well. ive had these boxed away for a while now waiting for a time to give them back. We work together so I see him every weekend and now I'm just wondering what to do here cause I know once I give him this box it'll rip him apart. should I give it to his roommate or just do it in person and deal with it cause these are the things I feel like he would want back. I dont know what to do. Helppp!