Parents Who Use Their Kids To Compete With Other Parents?

I have this acquaintance that my kids occasionally have play dates with his daughter. When we go out in public my sons get a lot of complements and attention mostly beacuse they are twins, and people seem to be facinated with twins. I notice that if someone dosent complement the acquaintance's child he will have an attitude the whole day, and take it out on me as if i can control waht people say and do. The last time we were out he kept pushing his kid's stroller right in front of my boys' stroller so she would get noticed before them. i can't understand why he is acting like this and why he is making this senseless thing such a competitive thing between our kids. Should i stop hanging out with him?... i mean this isn't normal/ rational is it? Has something like this happened to other parents?