You didn't even know what to reply. Was she really telling you that she had fucked a guy last night? Didn't she realise how much that could hurt your feelings?
Before you could think any answer he texted you again:
L: "He has just left after we spent all night fucking. OMG David, I was so drunk I left him do to me whatever he wanted!"
Y: "But are you ok? Did he do anything inappropriate?"
L: "Are you kidding? I've never felt better."