My pupils are just naturally quite dilated?

Well I think they are. They are normally quite big and then some boy noticed (who is SO annoying and who I really dislike!) and was like, 'OOH your pupils are really big... That only happens when you like what you see ;)' And he is like some nerdy boy (not saying there is anything wrong with being clever!) but I have a strong dislike for him for reasons to long to explain but anyway it has really annoyed me! Like who does he think he is?! And he was really serious and started telling everyone about it. I felt really self-conscious and he just told loads of people. I mean why do my pupils always dilate? I have heard that when you look at someone you like they dilate but I mean I am a generally happy person (sorry, it doesn't really come across in this!) so is it because i'm happy? And I also wear contact lenses, would that make a difference? Thanks! :)