My Dearest [Wife's Name],
Happy Birthday to the most incredible woman I know! 18 years together, and with every passing day, my love for you only deepens. You are my greatest adventure, my biggest blessing, and the love of my life.
You fill my life with so much joy, laughter, and endless happiness. I am so grateful for every moment we share, for your kindness, your strength, and your beautiful heart. You truly are a gift to me in every way.
Thank you for being my partner in life, my confidante, and my best friend. You make our house a home and make every day brighter just by being you. Growing older with you is the best thing ever, and I love you more than words can express.
May your birthday be filled with all the love, joy, and happiness you bring into my life. You deserve all the wonderful things in the world today and always.
Here's to celebrating you, my amazing wife, and to many, many more years of creating beautiful memories together.
All my love,
[Your Name]