Arshi - I second what Blu and Nicole said about there being an A or at least a fantasy of an A or a different life. My W couldn't wait to get everything done. Within a week she wanted out of the marriage, sell the house, and get everything separated. She had an EA, even if she doesn't recognize that it was an EA, with a guy who was going through challenges in his marriage and they bonded over that. He even physically made a move on her and she refused to talk about it with me. This was when I was still weak and not having found DB, that I just kinda took it meekly and didn't give her some repercussions.
At one point after BD, she told me about her fantasy of moving to a bigger city and having a downtown condo and living a large life. So, even if she wasn't contemplating an A with this guy, she was definitely in fantasy land. With DB, I finally got out of her way and got my space and now she's dealing with whatever fantasy A or real A that she thought she was getting into. She was also on her phone a lot and leaving rooms to chat or text etc. It was ridiculous.
But yeah, doing everything quickly and moving so fast is very suspect.