We flash back to the night Ioan gruff'd money in Andrea's face to get her out of the apartment -- a night, mind you, in which Andrea was in the middle of the Fake Harrassment scandale with Juliet and was therefore currently sleeping with Logan Echolls and could have gone to his place, but whatever. Andrea CLAIMS to Olivia she had nowhere else to go, and this appears to have been sincere on her part so perhaps she just forgot about her other storyline in this moment, and this of course ends in them drinking wine and falling into each other's genitals.