I find it interesting that lack of sex was an issue in your marriage (your husband wasn’t very willing), but now when separated he seems to all ready to go any time you call! I wonder if it’s manipulation now and if you get together, amount of sex will go downhill again.
Oh yeah if you aren’t a couple and it’s all casual, no need to tell him. I misunderstood that things are getting serious and you are interested in a serious way.