what do you do when you have two passions?

Do you mean as a career? Then you should take a few things into account. Which one would you be the most dedicated to? Which one would be worth spending the most time on? Also, which one are you the best at? Which one do you think you'd be successful at? But, you should also think about whether having to do it for work will take some of the joy away. After weighing those factors, you should choose the passion that best fits the criteria. And you can always do the others for personal pleasure.