River might understand, honestly. Given how she made and kept herself a child for years so that her parents could have the chance to raise her up as a delinquent even if they couldn't raise her as their baby and she was the one who actually had gotten them together. All during that time, Mels had craved family, and she had craved love, and she would have done anything within her power to do it. Frankly, she had done everything in her power to find them, even if it meant that eventually she would need to kill the Doctor. Who was now her husband. Complicated, that.
"We can always order takeaway and have it delivered. I'm not a big fan of fast food. Not here and now, anyway. Do you have a particular food you like? I've got menus from everywhere that you can think of." Melody Williams cooked occasionally, but given how busy her life was, she tended to prefer things that other people made and the adorable people who delivered them. It wasn't that she did it entirely so she could flirt, but the flirting was a rather large bonus.