You shouldn’t open doors for her and offer to drive and plan romantic dates at first, and then stop doing all of those things once she becomes your girlfriend. You should still do those things even though you have her. Even though you are confident she isn’t going to leave you.
If you stop holding her hand during long walks and stop offering your jacket in the cold and stop wearing that cologne she loves, then she is going to feel like you are taking her for granted. She is going to feel like she is the one doing all the work. She might even feel like you are no longer the same person she fell in love with in the beginning.
You had to work hard to get her — but you also have to work hard to keep her.
She already loves you, but if she feels like you are disrespecting her or unappreciative of her, then there is still a chance she will walk away.
She wants to be acknowledged. She wants to be seen. She wants you to look at her the same way you did when you first met and were in puppy love.
She doesn’t want to wonder what happened to the romantic man she fell in love with a long time ago. She doesn’t want to feel neglected, because even though you treat her decently, you never go out of your way to impress her the way you did once upon a time.
If you want to keep her, don’t let yourself get lazy. Don’t take her presence in your life for granted. Don’t assume she is always going to be there, even if you stop treating her like your first choice.
She needs you to flirt with her, even though you are already a couple. She needs you to surprise her with cute little gifts and send her adorable texts from time to time. She needs you to make her a priority the way you did in the past.
She doesn’t want to wonder whether your relationship has lost its spark. She doesn’t want to question whether your best days together are behind her. She doesn’t want to consider the possibility that you were good for her in the beginning, but have nothing more to offer her in the future.
If you want to keep her, you cannot let yourself become lazy. You cannot stop calling her beautiful and whispering I love you. You cannot stop looking at her like she is your favorite person in the world and you feel lucky to have her.
You have to put as much effort into the relationship as she has been putting in. You have to treat her like the girlfriend you are desperately trying to impress, even after she becomes your wife.