Heidi Montag says it was ''love at first sight'' with Spencer Pratt.

The 'Hills' star marked the couple's nine year anniversary with a gushing tribute to him on Instagram, where she described every moment with him as a ''blessing''.

Captioning a photo of the pair clutching their young son Gunner Stone, she wrote: ''Happy 9 year anniversary! It was love at first sight. I knew my life would never be the same. You are my soulmate, my heart, my soul, my best friend, my everything. We have fought through so much to be together. Every moment of it has been such a blessing. I knew I had to follow my heart and have faith in love and in you. Best decision of my life.

''Thank you so much for our son! This is been the best 11 years of my life. It continues to get better every moment, every day, every year. I love you more than I'll ever be able to tell you! I didn't think our love could get deeper until @gunnerpratt arrived! Not only are you the most amazing husband, you are the most amazing father! I can't wait to see the journey life has in store for us! (sic)''

Heidi had previously revealed her son's birth was ''chaotic'' and Spencer had to act like an ''air traffic controller'' during the baby's arrival.

She shared: ''He [Spencer] was like an air traffic controller, it was chaotic. There were crystals being rushed in and our own personal camera crew were there too, one videographer and one photographer, and he was trying to co-ordinate everyone. Later my mum arrived from Colorado. Then Spencer left the room so my make-up artist Stella stepped in. At that time I needed someone to concentrate on me and not everything else and Stella did that. It was a circus.''