From last night... (KC)

There's one more exchange. from the timestamps, it would have taken place after Jenna and Karen left the club, before they got home.

Jason: ur sister is awesome, Jen
Jenna: tolf you
Jenna: told young
Jason: lol did she tell yu what she did
Jenna: yah. :)
Jason: u arent jealous?
Jenna: naww....
Jenna: pullin into my driveway now, g2g
Jason: night, crazy. tell Karen i said goodnight, too

You put down the phone and head downstairs before you get caught snooping. It was the last text anyway. Your head is spinning. Jason had met up with Jenna and Karen at the club, and something had happened between Karen and Jason?
You need a shower of your own.