Curious about size?

Okay... so I don’t know how to really word this. I’ve been dating the same guy for 6 years now. We started dating when we were in our early teen years so we’ve both seen each other grow into our bodies. He’s always had a rather large penis... but lately it’s noticeably bigger. One day, it was normal and then we went 2-3 weeks without any sexy time, and when I saw it again it was very much waaay larger. I’m just curious if there’s anything that would make it bigger so quickly and naturally? Idk, I sound crazy 😂

Edit; He is very tall and slim. Always has been. Lately he’s been working out a lot and gaining a lot of muscle. But I don’t think the two are related.