Your e/m to your xH was uncomfortable to read b/c while seemingly sweet on the surface -- it still comes across as major pursuit. Which of course means he will keep distancing -- which is exactly WHY he didn't acknowledge you on MD. I understand his reasoning as to why he didn't do it b/c he felt it would raise your hopes.
IMO outside of purely business-related -- unless your xH initiates contact with you first -- you shouldn't initiate any contact with him -- unless you would also contact your next door neighbor, the guy who pumps your gas or a co-worker's H in the same way.
For example you would NOT have sent that type of Happy Father's Day greeting to any of them -- and you shouldn't have sent it to your xH. You need to think of him as dead to you -- b/c he is not any part of your life now. He will always be a part of your children's lives -- but the xW is NOT part of that equation except in the most tangential sense. This can change -- but it never will if you keep pursuing him -- no matter how obliquely.
And if you harbor any desire for a chance of potential future reconciliation -- it serves you best to distance yourself and make yourself less emotionally available. Create mystery! So until your xH is the one to pursue you -- you should treat him as an acquaintance -- no more and no less. Yes, be kind and cordial -- but offer and expect no more from him than that.
