First time today.

Today I had sex for the first time. it wasnt as good as I thought. I didnt cum. I don't know why? it always takes me forever to cum with blowjobs. but when I jack off to porn I cum within minutes, when I jack off to thoughts of my girlfriend it takes me...

forever also. why is this?

well it was your first time.
you probably just need practice and to learn technique.
as for why it takes you so long, maybe you're not that attracted to your girlfriend?

Ugh. maybe. how do I tell her?

don't worry, My first girlfriend I did not get off in for a while. It came, hahaha pun. practis maybe? don't worry about it, I know a few people who had the same problem