Black Eye Guy
Taking over the World!
Becasue of all those reasons you said, if she had taken that moment to say it, he would have believed it. And if she did she would have taken that moment.
Edit: Oh and we know from experience that Buffy has no problem taking a moment to tell people she loves them, In season 2, Buffy takes a moment to calm Angel down and tell him that she loves him, even though the portal was opening behind him.
And in season 5 The portal was open, Buffy had seen a bolt destroy both a street and a building, and a dragon come out of it, but she took the moment to tell Dawn she loves her.
Edit: Oh and we know from experience that Buffy has no problem taking a moment to tell people she loves them, In season 2, Buffy takes a moment to calm Angel down and tell him that she loves him, even though the portal was opening behind him.
And in season 5 The portal was open, Buffy had seen a bolt destroy both a street and a building, and a dragon come out of it, but she took the moment to tell Dawn she loves her.