You weren't going to go because you couldn't get your wife to state that the OM will not be there. Well she now has stated he will not be there, so now I think you should go unless this doesn't have anything to do with the OM?? That will really set off a war if now you won't go even though the OM won't be there. Then she can use that against you with the daughter. Just go, this is your daughter's day. If OM shows up then leave. I don't think your wife would risk being the reason why you left the daughters B-Day party.