Would you be pissed?

Me and the boyfriend live together, he left his Facebook open on a photo of another girl probably forgot on his way out to work and I've used his laptop for things all the time so it's never been private, checked his history and he had been scrolling through her photographs? Since day one I haven't looked at another guy or even thought about it. I'm so fucking pissed off just because I know our relationship is going kind of slow at the moment, he's stressed with work and we don't really see each other much except from when we both finish work. What the fuck. Am I being over dramatic?! Would you be pissed off. I do literally everything for him. EVERYTHING!

I mean I know I'm not the best looking female on the planet but at least close the damn page!