Context #1
Don: I have to think about so many things. It’s driving me crazy.
Kelly: Well, do you have to make your decision about all of those things now?
Don: I have to decide if I want to buy these two different suits, but I have to finish this work first.
Kelly: Then don’t worry about it for now. You can cross that bridge when you get there.
Context #2
Chad: I’m worried that my girlfriend’s parents won’t like me when I meet them next month.
May: Why are you so worried about it?
Chad: I just can’t help but think that they won’t approve of our relationship.
May: You don’t even know what’s going to happen. You can cross that bridge when you get there. There’s no reason to worry about something that hasn’t happened yet.
Meaning: The expression "Cross that bridge when you/we get there" means to not think about a specific topic or situation until you have to finally face it, because there’s no point in worrying about something that hasn’t happened yet.
