Well, he could have forgotten, like he forgot Darlene was his sister. There's been hints that there was something between them in the past, like last week the way Angela said she thought she'd never have to miss them. I think they're saving that reveal for the finale.

I think Eliot and Angela were married. She kept saying "I do" in his dream in episode 4 and she was wearing a wedding dress. Plus the way Darlene said she was family in this one made me think it was more than just having known her since childhood.