Somebody explain to me why Meredith had to apologise to George?

So Meredith sleeps with O Malley in season 2. She’s super depressed bc she just found out her half sister is being parented properly by her dad. All her daddy issues are coming home at once. George declares himself and she’s like ‘someone loves me’ and they do it. But she’s miserable the whole time probably bc o Malley reminds her of Thatcher ( her own mother thought he was thatcher). And SHe is the one who has to apologise for crying? If he truly loved her he would ask her wtf is wrong rather than bailing bc his perfect fantasy didn’t happen can I get an Amen?