Would you be okay with your husband asking another woman to smoke weed together?

My husband has been texting a married woman and apparently they’re friends but I just saw his text saying, “let’s get baked.” And he picked a day but he hasn’t told me anything about this. Would you be concerned? Also he keeps deleting the messages. Would you leave him? How would you approach this or handle it? Would you confront him beforehand or just let things unfold?