<human>: Summarize the given text in a few sentences.

So we've been together for a little over a year and a half and just recently found out I'm pregnant. 
A while back (probably 7 or 8 months ago) I went through his phone one night and found he had dating apps that he'd been searching through. I confronted him about it and he tried to say it was old and that he was searching for someone for us to have a 3some with (that was a discussion at the time.)
Well tonight, after he went out and I stayed home, something in my gut told me to do it again. So he came home, drunk, and passed out. My pregnancy has me waking up every couple of hours so now here I am and I went through his phone again and I find not 1 but 2 dating apps, both of which he's been messaging girls on as recently as this week!! I started to think maybe this is a drunk thing he's doing, when I notice the date wasn't tonight, but Thursday night, when he was home with me.
What should I do? How can I confront him about it without him trying to make it my fault for "invading his privacy" and "breaking trust," which is what he said last time this happened... he's the one breaking trust by being on those apps, right???
<bot>: my boyfriend of a year and a half is on dating apps and I don't know how to approach him about it.