Somebody please tell me why my absolutly straight boyfriend is wearing female panties? Its upsetting! I feel like its for perverted reasons!

My boyfriend is not gay. He is a very straight arrow kinda guy. But i recently found out he is wearing female panties. I feel like he is cheating on me when he does it. He does not do anything else feminime like that. He wears female panties, and thats it. He doesnt really think its a big deal. And its not. But i dont want my guy doing it. When i ask him why, he doesnt know. ” He just likes them. ” Please help me!!! I hate it