How wuld yu know if yu are dating a man or a girl or a "teenage boy"?

ok so i hav ds frend dat tawks about ds guy alot..but get ds; shs never seen him or tawkd to him on da fone..lyk, wat da hel?? sh met him on a website nd sh tells me dat dey txt al da tym nd hs alwaes sayng dat hs stoned and al dat nd he wil alwaes come ub wth xcuses to y he dusnt cal hr..i told hr to dump hm cos sh cn du waaay beter..help! how can i convince hr dat he myt b an old man?? and how wuld yu know if hs not hu yu think he is??