What does it mean when a guy makes eye contact with you while smiling, then looks down?

There's that guy in my neighbourhood who stares at me lot when Im not looking, smiles at me a lot, keeps making fun of every word i say playfully (we both laugh). We both play cards a lot.

One day , him and I were playing cards and there was a man sitting with us. Before he left, he said "I'm gonna go and come back at night. Oh and (to me) you better shave him his beard." He had little hair. When the man said that, me and him looked at eachother and smiled making eye contact, and we stayed for like extra 3 seconds keeping the eye contact and smile, then he looked down to his cards and we continued playing.

ps, he has a girlfriend.