Although that is a legitimate reason for Elias to be tired, Texas changes the subject, complaining about Elias leaving dirty clothes scattered around his room. She picks up one of his socks, but then realizes that it's all crusty with cum... was Elias jerking off into the sock?! Elias is so flustered that he becomes FULLY alert, defending himself by saying he couldn't help it when he heard that loud sex last night. He didn't want to cum all over his blankets, so he HAD to use a sock.
Texas is flattered that Elias was so turned on by the sounds of her having sex, and offers to apologize for keeping him up last night... by letting him fuck HER now. After all, putting his cock in her ass is much better than putting it in a sock!