While I agree with all of that, what about his obligation to help the interns? Working 5pm-1am isn't going to help the interns much. It sounds like the OP mig

While I agree with all of that, what about his obligation to help the interns? Working 5pm-1am isn't going to help the interns much. It sounds like the OP might have been raised with a certain style of work ethic. Measure your partner's success based on what he adds to the product and the success of your technical employees, and how well he enables you to go out and handle your side of the equation.