Lexi let him brush past her, well, eventually, she blocked him for a moment, just to give him a look. Probably one of her most judgemental. He was gonna screw this up and ruin the best chance he had of actually having something good in his life. He'd gone from Katherine to Sage and back again and sometimes she really did just want to slap him upside the face for being an idiot.
"I know you well enough Damon. Better than I want to, and for whatever reason, Elena loves you. Loves you enough to overlook every damn thing you are capable of and every way you could screw this up and hurt her. Like this way. So go fix it meathead."
That said she let him move past her.
He had better things to do than fight a fight he couldn't win.