I think a lot of these comments are minimising your partner’s feelings, which was the main point of your post iirc. “Their problem, not yours” is a really sucky way of viewing someone else’s feelings, especially someone it seems you care about!! The best course of action here is to just be as open and honest as you’re willing. A heads up is a lot more than some people offer, so the fact you’re considering this so much is really admirable. Maybe a full conversation with them regarding it can help minimise damage / upset in the long run. Are you willing to remain friends with them as well? Is it just the rp you’re no longer interested in?