Oliver remembers to tell the truth.
Remember when Oliver finally moved on and became more open with the people closest to him? That he’d stop hiding things from people and stop keeping things to himself? Yeah, it’s hard to when there’s the big elephant of Oliver’s son in the room. Sure, Felicity kind of exploded on him when she found out (in a now erased timeline) about Oliver keeping his son a secret. But it’s only fair to let the guy breathe for a second. The news would knock the wind out of anyone given the situation. But let’s just hope that he doesn’t keep Felicity in the dark for very long, especially after that tragic ending to the midseason finale.