Advice please

becca • This is my 3rd pregnancy I have 2 boys who are 9 and 4 I am expecting a lil girl July 18
This doesn't have to do with pregnancy but me and my kids father haven't been together for the last month now we have a 4 yr old he hasn't seen his son in this month or even Tryed seeing since he left to be with the girl he was sleeping with while we were together am I wrong to not telling him about are sons pre school graduation