If I was you in that store, I'd have picked up a toy and walked right passed him, and make sure I was in his sight while I was paying for it.
I was in Asda once and they have a little shelf with some pony merchandise on it. Being 13, people find it even 'weirder' when I'm looking at that kind of stuff. What, did they expect me to be looking at the 18 rated video games or something? Anyway, my family was off somewhere else so I guess I was in the clear for a few more minutes (They don't know yet). Then, suddenly, this other family with a very young daughter come walking over. I moved up a bit so they could have some room and the girl reached for a brushable Princess Celestia and Pinkie Pie or something. I then glanced at her, smiled politely and said (In a friendly voice) "Oh, I like that one, too!". Her parents then pushed their daughter away giving me really worried looks like I was some kind of creep. I just looked away and went back to browsing.
Yeah, people are going to treat you weirdly for 'going against the flow' but my only advice is to act as friendly as you can and don't shy away, that usually just makes it worse.
Oh, and here's the particular toy I was talking about: