Karrueche Tran isn't hating on ex Chris Brown for sending googly eyes to his other ex, Rihanna ... she actually says she can't blame him 'cause she'd do the same thing.

We got Karrueche leaving Catch in WeHo -- perhaps a little drunk -- and asked what she made of Rihanna's sexy Crop Over outfit and Chris' comment that got fans all riled up.

She's joyfully honest -- telling us she'd love to learn RiRi's secret to getting that type of a bod ... but then admitting it probably ain't gonna happen for her.

Never say never, though, KT ... Kim K's only a couple inches taller and the reigning queen of thick.

As for Chris' googly eyed comment for Rihanna, Karrueche sees the rationale ... even if he probably ain't the best one to express it.