Relationship advice..please

chloe.x
So a little over a year ago my boyfriend left his iPod in bed while he went to work and me being me yes I looked on it, I looked on Facebook and snapchat, wasn't really anything on Facebook that id not seen before but while on snapchat I noticed a blue triangle next to some girls name, so I swiped open the convo and snapchat being snapchat it doesn't save it but seemed to have saved a few of the convos even though their was missing bits there was enough to show he'd been practically sexting some girl, looking back on the dates, there little fling started before I even knew him but carried on even know he told me all this lovey dovey bullshit. So I confronted him about it and all he was bothered about was don't go through my stuff, ha! So the storey was it was his friend, who was using his snapchat to message this girl, I hit the roof I cried until I couldn't anymore and I decided to leave it at that even though I've never believed that bullshit storey i give him another chance. So now a year later, were still together and I love him to bits, but he left his Facebook logged in on my iPad so yeah why not have a peak, and her name surfaced again, they aren't friends on fb but they've been speaking about the "person" who was meant to be messaging her and she doesn't seem to know who he is very well like wtf? And he's been searching her profile quite a few times with the last time being 2 fucking days ago! Girls advice please, sorry that turned into some sort of rant lol x