Britney Spears' Loved Ones Concerned With Paul Soliz Reconciliation

Britney Spears is sliding back into an old relationship ... hanging with Paul Soliz again -- and, her loved ones are worried about how quickly she's seemingly run back into his arms.

Sources with direct knowledge tell TMZ ... Spears' friends and family -- including her brother Bryan, we're told -- are confused and concerned she's already hanging with PS again just weeks after the two split up under rocky circumstances.

We're told Britney let everyone around her know at the time that she was finished with Paul ... going as far as telling her gate guards to take him off the guest list for good. So, naturally, the chummy lunch in Malibu earlier this week raised some alarm bells in her circle.

Our sources say those close to Brit are worried about Paul's criminal past ... and, we're also told Britney came to the conclusion that she felt Paul was just using her. That's exactly why some in her orbit are wondering why he's still around ... seeing how she came to this conclusion not that long ago.

Her loved ones are well aware couples can rekindle their romance and get back together from time to time... but our sources say they're still confused why they got back together so fast. Not just this ... but we're told her pals found out about them hanging again from pap pics as opposed to Spears herself.

Like we told you ... Britney and Soliz grabbed lunch with pals at the Soho House in Malibu Wednesday. Weeks after Britney proclaimed herself "single as f***" via Instagram -- clearly throwing shade at Soliz, or it seemed at the time.

The two have had a rocky relationship, to say the least ... they had a huge blow-up fight at the Chateau Marmont nearly landing Brit in an ambulance -- although she later claimed it was just a foot injury.