Making room for a stepdad doesn’t have to mean less room for your dad. Hearts aren’t studio apartments.

Affection does not come in a fixed quantity that has to be divided. Liking a stepparent can feel like a betrayal because it seems to take something from your dad, as if there were one chair and somebody has to lose it, but attachment does not work like floor space. Adding a person adds a relationship. Nothing is subtracted unless you choose to subtract it.

If you are carrying guilt about this, you might let both things be true for a week and see whether anything is actually lost. Being decent to the new person needs no announcement. Going slowly is allowed, and so is not calling him anything yet.