Is my dad going through a midlife crisis?

may be sign of depression, or just a mid-life crisis. Talk with him and see what is bothering him, and obviously the loss of job is a big factor - man cannot support his family. His routine has been broken, and he fears (like all of us do once 40 hits us), that no one will hire us, making us feel needed. See if he has the ambition to start his own li'l company, or to do some volunteer work. And the losing weight has to be done with a doctor's approval and check his blood pressure, etc. Tell him you have no interest in the tattoo, as you and he would be doing it for the wrong reason.