A simple "Hey, I'm interested in you and no pressure, but I'd like to take you out on a date some time." is generally the most straight forward, and easiest way
Figiting, getting overtly embarrassed, and inability to talk straight are massive turnoffs for people.
If the person is legit, it'll either be a positive response, or if they are legit and reject you, they'll be honest "I'm sorry I'm not interested" or something along those lines. If that's the case, and be ready for that, just reply with a simple "Not a problem. I need to get going, but I'd like to still talk some time if you are free".
This response will help you out of an unsavory situation, and eases the tension on both sides.