I've also felt the same way as you. When I was 16ish and just starting to fool around I was very confused. Boners would pop up like wildfires when I hung out with guy friends and we fooled around, but with girls is was/is more about getting on her level and sharing really intimate things. I didn't know what to think as a younger guy because I really wanted to fool around with guys, but I knew that I absolutely loved having a girlfriend, however, I only had amazing sexual urges for them when I really got to know a girl and really liked her. That was completely, and still is, against today's 'norm' of young guys fucking every girl they possibly see. I just can't and don't want to do it.
Suffice to say, it's fucking confusing. A lot of people I would assume don't understand it - I hardly do - and I'm just now understanding myself that way. It's always going to rack my brain and fuck things up, but I'm trying to become more accepting of it and just see what happens in the future.