You are on his roller coaster 3b....You also know that you have to get off for your sanity.
As for the call and text...Let's be serious. Unless you are one of those people who stays up to 1-2 every night...Then why be disrespectful and do either to you? Seriously....You spent the day raising three boys. It doesn't matter if the calls were to you or the OW in the end.....They more represent a boundary crossing of basic human respect. You have your day to day life and that needs to be respected.
As for the boundary you made....Boundaries are only as strong you are. The stronger your boundaries are....the more they will be respected and successful. You know at a minimum that contact continues with OW.....So that means a cease to your friendship with your H....So really the only communications should be about kids and finances and definitely not about late night drunk burgers at white castle.
Be strong...Don't respond to text of a personal nature and live your life.