You can also make it more natural with just a small change, like so: - I came into your room last night while you were sleeping to close the window. - Last night, I came into your room to close the window while you were sleeping.

Thank you :D

For one, you dont need the second “I”. But in general to sound more natural, if you’re speaking, you break it up more. “While you were sleeping” is awkwardly placed and phrased, so I would change that part the most. Something like “ I had to close your window last night. Shit was so cold I dont how you were sleeping in that.” It depends on context but yeah you also want to avoid sounding creepy in most contexts lol because before the “and I closed the window” you’d be getting some weird looks