Sirius scanned the text... and zoomed in one particular example.
"I like this one," he said with a cheeky grin. "Keeping warm in bed," he read aloud. Then for good measure, added his own interpretation. "Although, generally, I'd think a nice warm body would be so much more pleasant to have. Heating charms are warm and fuzzy and all that. But a nice, warm body? Brilliant." Okay, so maybe Sirius was just being extra cheeky because he knew Remus would get unnecessarily shy about things like this. For some reason.