By a sound

SMACK SMACK SMACK, the sound of smacking has been going on for at least 5 minutes since waking you up. You can only assume its students having sex a few doors down the hall. Being a virgin the whole 'sex' thing is unknown territory for you, of course you've watched porn countless times but the fact you can hear the act being played out a few rooms down makes you flustered. Getting out of bed you bring you ear to your door allowing you to hear the sounds slightly better, SMACK SMACK "TAKE THIS FUCKING....SPUNK" you hear a girlish voice scream,
"Is that a girl? She must be riding his face talking like that" you whisper to yourself.

The smacking has now subsided and an eerie silence fills the hallway, "finally" you say returning to your bed.