S.G.
I was thinking that it wasn't a big deal until I read the part about his being from the area and the wife needing a break....
Why does the wife need a break? Is he a slob or is he a drinker? If he was abusive she probably wouldn't be throwing him out but leaving herself. I would be concerned with my children. I know a high school friend of my husband's would come by the house and even my children said he was weird. I never let the kids be around him alone and would take them out somewhere. A few years later he was arrested for molesting his step daughters. I would insist on getting to know this guy before letting him sleep over just so you know what you are getting into. If nothing else it would be a good time for kids to go spend sometime with grandparents.
All husbands (and wives for that matter) will have times where they seem more selfish and be a better spouse... it is how we learn to compromise in relationships.