how to tell when a guy is joking about liking you?

[Alice]

so this guy that i have never met before keeps on telling my friend (he hangs aroundher group) that he thinks im hot and he likes me i have never met him before?? and when i walk past his group his friends point at him and say hi and stuff but i think it might be a joke so how can you tell when a guy is joking about liking you

 

[Pleaseloveme]

pretending not seeing them..if he dares to come to me face-to-face,then i would answer his question..
but,i dont think that he is joking anyway..