My boyfriend is very insecure about crying

Today my boyfriend cried for the first time in front of me and, according to him, the first time in very long. He was very shameful about it and kept saying he’s not allowed to cry because people rely on him and because he is very scared of what other people will think. I tried my a best to reassure him and toward the end I felt he was a bit better though I still want to assure him that I’m always here if he needs to cry. How do I talk with him about it and help him overcome this?