Just what in the world is going on here?

Tuesday night, we catch Adnan Ghalib stopping by the Summit to visit with his main squeeze Britney Spears.

Last night, we catch Adnan slinking through the streets of West Hollywood after dinner with a new lady!

Could Adnan be running around on Britney? Don't forget - this is hardly the first time we've caught him out with other women lately!

Adnan's dinner date, meanwhile, loudly protested that she and the photog had gotten together for an innocuous business meeting. Sounds like someone's getting the business, anyway!