35 year old asked me out

so i’m 16 and i work at dunks. i’ve been there for about 4 months so i’m out working the front by myself as the other girl is doing dishes. this 35 year old dude comes in and i smile and say “hi how are you?” and he doesn’t respond, he just stares at me like this:

and so i’m uncomfortable and can tell he’s weird so i say “what can i get for you?” and he doesn’t respond just keeps looking like that so i’m completely uncomfortable so i pretend he said something so i say “i’m sorry what?” to speed up the process cuz a guy was behind him. he says “will you go out with me?” and let me tell you i was so uncomfortable i just started laughing and said no

i’m like “i’m only 16” and this dude SIGHS cuz he’s frustrated and goes “16...hmmm” and literally thought about it and goes “does anyone who’s not 16 work here?” and i’m like no only 16 and 17 year olds are working right now and the guy in line behind him was SOOOO uncomfortable and the creep turns to him and goes “i’m not gonna go here anymore if a 16 year old won’t go out with me” so i’m thinking that’s fantastic. he then orders his drink and i make it and just stares at me sipping his drink for 5 minutes as i clean the showcase and then he leaves. i cannot describe how uncomfortable i was. if you ladies were me and my age and this happened to you, what would you do?