Brit's Pap: "It was the best night of my life!"

Is Britney hooking up with a pap?!!! It seems the guy pictured above is the luckiest man alive right now!

Adnan grew up in England -- in fact, Britney asked our guys where he was just the other night, in her best British brogue!

And NOW, she's spending the night with paparazzo Adnan at the Peninsula Hotel?!!!

Here's what Adnan told our photogs tonight:

"I may have lost a lot of money [because I didn't take pictures while I was with her], but it was the best night of my life!"