Remus' shoulders slumped when he heard Sirius mention his jacket. His heart was fluttering madly, thinking about being enveloped in Sirius-Clothing. It was stupid and he quickly shook it off.
"Me? Drive? Are you mad? I'm holding on. Hold it still, I'm going to try this..." He awkwardly perched himself in the windowsill and then gingerly stretched one of is legs out.
It took a moment but he was able to get his leg over and the rest was easy. He clutched Sirius around the middle like a drowning man.