Agreeing to go out on a date with you. Planning future events as a family. Reading a pro-marriage book. Not going out with a usual group of single/divorced/separated friends on a Friday night for once. Etc.
Too many people focus on "nice." "He's being nice to me." Sometimes "nice" is a payback you are given to keep you right where you are.
I'm not saying that being treated rudely is better than being treated nice. I'm just saying there are a WHOLE HOST of things that "they're suddenly acting nice towards me" can mean.