Does cycling help build glutes?

As a part of my summer workout plan I (M18) decided to change my diet and cycle for about 5 days a week. It's been only 2 weeks (I started the first week of July) and I generally cycle for >12 miles in hot south FL weather at about 1-2pm after having a banana for breakfast. I like to think I have a good metabolism. I already see progress but I'm especially curious about how it affects my glutes.. they have always been comically small compared to my legs hahaha... to the point where my girlfriend says that it looks like it's "permanently clenched" lol and that it's "endearingly small" hahaha.. but after these 2 weeks it feels like my butt is getting bigger or something? i dont really care about it but im not sure if my eyes are deceiving me or something haha.. appreciate the responses..