He was sore, but he'd rather be sore than not have Severus. Remus rapped a bruised arm around him and kissed him. This time it was he who was a little rough, letting Severus know he wasn't some fragile thing. No matter what Severus did to him, he could face the pain. He was worth it. Just hopefully he wouldn't touch his ribs.

He also took the kiss to mean that Severus wasn't worried about them being together. Though he did still wonder why he asked in the first place.