Similar to this question, I'm looking for a word to describe a particular kind of smile.
It's the kind of smile I smile when I receive a sweet message from the girl I love, and just can't help beaming. The phrase which goes through my mind is 'smiling like a fool', but I somehow think there might be a more precise adverb (e.g. smiling sheepishly, which I don't think quite fits).
"I catch myself smiling ____ when I read her texts."
Which adverb fits best?