Yeah, my stbxah is super nice too. I ignore it because I have no idea if he is staying sober or not and I don't want to go down the road of "is he sober or is he not" way of thinking ever again. I'm done with those types of all consuming thoughts -- DONE. This is one of many reasons im divorcing, which should be finalized in the next couple of weeks. I don't want to spend precious energy worrying and wondering.
Does your husband and mine have hidden motives? Possibly, but my X's way of taking care of our kids has always been to buy them; he doesn't seem to know any other way to communicate as a parent, if you want to call that parenting.
Just stay sharp. If you have kept a journal, reread your posts and remember why your doing what you're doing, or reread your posts here at SR.
hugs!