He also continues to be friendly and even flirtatious with me at times, and then retreat to being a bit colder and more withdrawn. He’s made a couple of odd comments about other men finding me attractive lately which catches me off guard. Last night as he left after putting D4 to bed he stopped in the doorway and asked if “everything is going ok”. I’d been nothing but upbeat all evening, and just smiled and said “yup! You?” It’s all curious to me, and I consciously try not to dissect it too much.
Looks like he is fishing to see if you are still available as a plan B. You are right in not dissecting it since it will only drive you crazy.