1. Tell me more about [thing you are so passionate about you can’t stop talking about it]. Because what I’m really saying is “I care about what you’re interested in, and I take it as seriously as you do.”
2. I’m not going to tell you that you’re hot or sexy. Not because I don’t think that you are, but because I don’t think those words are strong enough for how I feel about you. They don’t convey the warmth or the vivacity that you hold within you. I will tell you you’re beautiful instead, because I think that does a better job of telling you that what makes you attractive is a combination of your physical and personalty traits. You are so much more than a great ass or a nice face.
3. I’m sad that you didn’t succeed at that thing you were trying so hard for, not because I care, but because you do. What you offer in this relationship is not an accolade or salary, I just want to be with you every day, and your goals and dreams become mine. For better and for worse.
4. I’m not saying that you are perfect. I’m just saying that I wouldn’t change anything about you. I love every single part of you, perfect or not, because that’s what makes you so unique and fascinating to me. I like you for all the ways that you aren’t like anyone else. What I’m telling you right now is that I will love you unconditionally.
5. Your personality is one of my favorite things about you. Yes, I think you’re pretty and yes, in my eyes you look like a supermodel. But what I love more is how well I get along with you and how much fun we have together. I feel like I would never, ever get bored with you, and that’s more important to me than the fact that I’m physically attracted to you.
6. I love the fact that you never cease to surprise me. You’re one of the most interesting people I’ve ever met, and I never know what to expect with you. I feel like I need an entire lifetime to figure out the person that you are and then some. Being bored is one of the risks of being in a relationship, but I never worry about that with you.
7. I don’t care what your friends think or what your parents think or what your coworker thinks. Your opinion is the only thing that matters to me, and everything else is relative. If their opinions are important to you, they’re important to me. But your opinion dictates all of that.
8. No, that outfit doesn’t make you look fat. And the reason I’m rolling my eyes is because yes, I understand that you don’t look like Jennifer Anniston, but who cares? Nobody looks like that. To me, you look great.
9. Few people know a lot about [insert any hobby or interest here]. So even though I’m completely clueless about it, I love that you’re passionate about it. And I’ll do everything I can to learn more about it from you because I’m interested in things that interest you, even if they don’t interest me directly.
10. Your insecurities are some of my favorite things about you. That dimple you’re embarrassed about or that laugh that you hate or the freckles you wish you could erase are the same exact things that make me love you all the more. They make you memorable and different and interesting and a breath of fresh air. I understand that it’s hard for you to get over these insecurities, but just know that there’s someone out there (me) who loves you all the more for them.
11. Please stop saying you’re an “ugly sleeper.” Because I’ll never stop thinking you’re adorable when you sleep, whether you’re in a peaceful slumber or in a drunken stupor.
12. I love how much you love to read. Because what I’m really saying is “I love how intelligent you are. I think you have a lot of interesting things to say and I am genuinely curious about your opinion and your stance on certain issues. I love the fact that I feel like I can learn something from you.”
13. You’re cherished. I want you to know that you are one-of-a-kind to me. I treasure you because I know that girls like you don’t come around very often. Whenever you’re feeling down or not quite like yourself, I want you to remember that you’re the whole world to me.
14. There are so many little things about you that I love. Your cute laugh or the face you make when you’re concentrating or the way you bite your nails when you’re nervous. I love learning a little bit more about you each day, and I don’t ever want to stop.
15. I’m proud of you. And I don’t mean that in a patronizing way. I just mean that I think you are so impressive and admirable and accomplished and respectable. I want to support you in whatever career you want to do, but more than that, I’m proud of you for the kind of friend and daughter and sister and person that you are. 
