Jessica Simpson warns Britney Spears against overspending amid financial problems

The singer shared this advice while leaving LAX on Tuesday… while chatting with a friend who was asking her about this topic — namely the fact that Britney's financial situation is a mess.

Watch… Jessica admits she takes a lot of luxury vacations herself, which can get expensive quickly — unless you have a mama bear who's willing to help out sometimes, and it looks like Jessica does. Anyway, they eventually get to Britney herself… and GS has ideas.

When I brought her our reports on Britney's spending Much more than you do These days – especially when you're flying – Jess admits… First class flights can definitely burn a hole in people's pockets, especially if you're not careful.

Remember… we're hearing from our sources that Britney isn't being careful at all — so Jessica's words here totally apply — but still, she's also offering Britt some grace.

While these trips can be expensive…she jokes that they're always worth the memories.

As we told you at the beginning… the pop princess is at risk of bankruptcy, spending huge amounts of money on frequent trips to French Polynesia and Hawaii. We've been told Britt travels regularly privately and donates hundreds of thousands toward her accommodations.

Hollywood psychiatrist Dr. Charles Sophie until Expressed concern For the sake of Britney's health…which suggests that the artist needs medication and perhaps even a new conservatorship to keep her in check.