Flirt more with him and pay attention to how he responds. If he seems to respond positively to your increased eye contact, smiles, attempts to sit next to him, leaning in, brushing his arm/hand or small touches, etc., then include continue the flirting and add compliments to your conversation. Tell him why he is special to you. Try to increase the amount of time you spend together. If after all of this, things are still going well you can tell him you have a little crush on him and see how he responds. (It should be totally obvious by that time.) If he rejects you, it is not the end of the world. Take a chance but save sharing the love poetry until you're in a committed relationship.