I've been trouble accepting that my bf has sex with his ex. they were together about a year a while back.

The relationship is well over.
There's no chance of him going back to her, and I completely believe this.
But they did have sex. The bf is my first. We have had sex now.

Am I being unreasonable?
I just... can't seem to accept the fact no matter what I do. I love him, I really do... but

them together - I feel like they broke up only because it was necessary, he was thinking of long term with this ex.

I dunno
i'm confused