The 39-year-old star struck up a relationship with the 'Drive' actor after meeting on the set of 'The Place Beyond The Pines', and Eva admits playing parents to a little boy in the crime drama made her fall even more in love with Ryan because he was so gentle and caring.
Asked whether her beau was good with kids, she enthused: "He's really good. He loves babies and he loved playing with the little boy we used in the film to play our son. It was adorable to see him in that light.
"There's one intense scene in particular where everyone has been screaming, including the baby. The beauty of that scene comes when Ryan picks up the baby and he immediately calms down and starts to fall asleep on him. That's just magical."
The A-list couple - who have been living together in New York for a year - might be two of the sexiest stars in Hollywood, but Eva insists she is attracted to Ryan because he doesn't pay any attention to how he looks and is refreshingly low-key about his image.
In an interview with The Sun newspaper, she said: "I know a lot of actors who are totally obsessed with creating a certain look, whether it's very polished or very street. I definitely don't need that in a man. A real man doesn't fuss about his appearance."
The Cuban-American beauty is widely recognised as one of the sexiest women in the world and although she is happy to be a sex symbol she hopes people appreciate her other skills on screen.
Eva explained: "Sexiness can be great and powerful as long as that's not all there is to your character or what the director wants to draw out of your for your character.
"Being sexy is just one component of who I am - it's a thing I can be. It's a side of myself I can tap into, just like I can tap into my funny side or my dramatic side. It's not what I am."