Do not let yourself get lazy. Do not assume that you can slack off because she has been your girlfriend for years and the relationship has gotten comfortable. Do not let the sparks fade away. Do not stop chasing after her the same way you did when you first met her, when you weren’t sure whether she would ever agree to a date with you.
Take her on dates you have never been on before. It doesn’t matter whether you have already been to every movie theater and restaurant in your town. Get creative. Take her to fairs. Challenge her at bowling. Go cherry picking together. Watch the sunset on the beach together. Snap photographs and glue the results into a scrapbook together.
Do not let the relationship become boring. No, you cannot whisk her away on a dream date every single weekend, and she is not going to expect you to — but you should not let months go by without reminding her of how much you love her, without treating her to something special, without making her feel like you still want her as badly as you did in the beginning.
If you want to keep her, then you have to exert as much effort as you originally did to get her. You cannot stop complimenting her and doing sweet things for her because you assume she is going to stick around no matter what happens. You cannot take her for granted because you are used to having her around and cannot remember what it was like to exist without her.
Even though you already feel like you know everything about her, you can never stop asking questions. You can never stop having late night conversations. You can never stop learning more about her because she is evolving as the years pass.
The worst thing you can do is treat her like furniture. Instead of watching television during dinner, turn the electronics off so you have the chance to talk. Instead of catching up with your friends on weekends, set aside enough time for a date night out on the town.
Make time for her. Real time for her where you are talking about something other than who should finish the dishes and walk the dog next. Do not let your relationship turn into a predictable routine. Do not get too comfortable because then you will start taking everything she does for granted.
No matter how long you have been together, say those three little words to her unexpectedly. Pull her in for long hugs. Kiss her on the forehead without expecting sex. Remind her how much you care about her and how much you appreciate everything she has brought into your life.
Make her feel excited to see you, just like in the early days. Give her butterflies again.
If you want to convince her to stay forever, then you have to give her a reason to stay. You have to make her feel admired. And she will do the same.