When someone suddenly lifts someone else in an fit of enthusiasm we may say that he "swept her off her feet." A prince may do that when he rides up to the castle and sees the princess he has been thinking about.
I wonder whether that is what you mean. We also use the phrase metaphorically, when a man, for instance, is very generous and attentive to a woman, so that she is becomes very attached to him and doesn't think of anyone or anything else.
Thank you very much for all the answers above. I didn't make it clear. This picture is what I mean. I don't know why I said it's like a prince lifts a princess up. Maybe I have seen too many Disney animations.