Remus just happened to be biting into a large chocolate covered strawberry when Stephen made his comment. Regulus might chide him for letting his weaknesses be known, as he had during an early conversation where he 'used' Remus' love of chocolate to get him to stay and talk. But, Remus didn't mind this particular weakness being known.
It wasn't as if they hadn't given the world his biggest weakness in coming out.
"Mm, I couldn't move in," he said with a grin, once he'd swallowed the strawberry. "But, Astoria is certainly one of my favourite people these days." And not just for her brilliant choices of sweets -- though, chocolate helped a myriad of ills.