You can confess to liking Cove romantically as early as Step 2 and in Step 1 the MC can say he's extra special to them. And if the player wants to imagine their character and Cove are soulmates/in love from the moment they met, that's sweet and okay, however having the game itself go on about how eight-year-old children are so genuinely in love with each other could easily get awkward or even uncomfortable, ahah.
That's why you can't officially start declaring that it's true, life long love until they're old enough to more reasonably understand those kinds of serious feelings. I hope that makes sense.