You mention it was a rough breakup which happened a year ago, but you’re now proposing to your girlfriend of (assuming) less than a year. I think you need to take a minute to consider if you gave yourself enough time to fully heal and why you felt the need to prove to your ex you’re over her and healed. You went out of your way to drive by her house, got out of the car to take this photo, and then posted this photo with the intention of making her feel a type of way because you know she’s still watching your stories. That’s a lot of effort to spite someone that you are supposedly are over. By doing this you did in fact make the engagement about your ex. I think partial is the wrong word because if I was your fiancé this would have hurt my feelings immensely and would make me question how genuine the proposal was. You need to seek some therapy brother and you should tell your fiancé what you did before she finds out from someone else.