Liv Tyler says David Gardner is her best friend.

The 'Leftovers' star, who gave birth to a baby boy, Sailor Gene, with the soccer agent on February 11, gushed about her ''beautiful'' boyfriend in a touching post on Instagram on Thursday (05.03.15).

The 37-year-old actress shared a photograph of David standing outside retailer Buy Buy Baby, with the caption: ''Who's your daddy!!! davidgardner76 beautiful father best friend Thank you for making me smile so big and laugh so hard and loving me so much.''

The brunette beauty, who also has 10-year-old son Milo with ex-husband Royston Langdon, started dating the British talent manager, who has son, Grey, seven, with ex-wife Davinia Taylor, last summer after being introduced to him by mutual friend Kate Moss.

And a friend previously said: ''They get on very well and are really enjoying spending time together. He flies to New York mostly to see her and they feel very comfortable together.''

''He is very charismatic and a real gentleman and she appreciates that about him.''

The 'Lord of the Rings' actress is also clearly besotted with the new addition to their family, as she also shared a new photograph of Sailor's feet, with the caption: ''I'm so in love!!!!''