Sigh..i need a little help here..?

i've seen this guy around for some time and actually there was once when i had a bet with my older sister who's 26, i'm 18, that i'll p him a note with my number on it..so on that day, the both of us went into the shop and browsed at the clothes and stuff,then my sis went in,got a baby clothing and went to ask him some qns,i was standing beside her and occasionally turning around to look at the guy,hopefully there was some eye-contact but there wasn't and he looked really unfriendly and aloof,i don't know but maybe he's just like that or perhaps shy? we walked in and out of the shop a couple of times, with me still trying to muster my courage to approach him,the last time we went in, he looked at us, i don't know if he was looking at me or my sis,my sis turned n check if i was making eye contact with him but i didn't because i dare not look at him and wasn't sure who he was looking at.i wanna p him that card but afraid of his cold appearance and what if he said he's attached?