The `Bad Teacher` actress only recently confessed to being in a relationship with the 35-year-old baseball star, but has now revealed she is particularly close to him after he tried to eat the last of her popcorn at the Superbowl in Miami in February, something she would usually not be happy with.
Speaking on `Late Night with David Letterman`, she said: "We were watching the game, and I was eating, and I was getting down to, like, the last couple pieces of popcorn.
"And all of a sudden, I see [Alex`s] hand coming in. Anybody who knows me does not put their hand in my food, especially when it`s close to my mouth.
"I said, `What are you doing?` And then I went, `You know what? I love you too much, I`m going to give it to you. You deserve it."
However the response from Alex - who has previously dated Madonna and Kate Hudson - was not what Cameron expected.
She added: "We started laughing so hard. Like, `Are you kidding me? Are you kidding me?` "
Cameron, 38, has previously revealed sex is her favourite "sport" and she is always in the mood to make love.
She said: "Sex is the sexiest word in the English language. Just the word is sexy to me. There`s something to it, don`t you think? Sex is my favourite sport.
"What`s the quickest way to get me in the mood? I`m always in the mood."