Yes, Ian's relationship with Jeremy can affect how he reacts to the news, but the reveal is guaranteed and, looking at the script, it's intended this way, not a bug. I think this is fine, for 10+ chapters people were all like, "oh Lena can cheat on Ian freely, there's no consequences for her, it's so unfaaaaaaair". Well, the consequences have just arrived.Does Jeremy rat out Lena to Ian regardless of what relationship status he has with both?