I'm sorry, you poor thing.
Sounds like you have your head screwed on though.
I've been through this. I was desperate for it to have been "just looking". Believed him. Except I didn't, really. Then I was pregnant after 3 years TTC a miscarriage at 12 weeks and IVF. And found more evidence. I still tried to believe he was "only looking". But it poisoned everything. Every little thing he did wrong, I'd look at him and think "you disgust me". Then he didn't have to do anything specific - I just couldn't touch him because I knew he'd done it. And also I'd got to realising that even if he had "only looked" (you're sooooo going to get that line!) that was ENOUGH.
I mean - it's never excusable, but our husbands are/were doing this in the early years, honeymoon period, TTC, no problems! We were HAPPY. So really, what hope he's scene change?
I didn't leave, because of my daughter. I led a resentful, miserable half life for 4 years.
Then I found MORE evidence. He leant me his old phone, although the texts had been deleted the numbers and times still there. About 2x a month for the previous 18 months - the life of that phone.
And here's the funny bit... HE NEVER WENT THROUGH WITH IT!!
HA HA HA.
This time, I just shook my head, and said "even if you didn't, and you did, this is ENOUGH, we're done."
Oh, OP! I felt so light and happy! A year on, my daughter is settled with 2 homes and I don't spend every day despising myself for staying with him, being treated like a total mug.
Oh and for someone who just looked... Once we'd split he wasn't so careful with deleting any more, so I saw both confirmed bookings, and one weekend (we stayed in same house for 4 months) he had a prostitute round to MY house.
People do not "just look".
Steel yourself for the bullshit, and hold firm. Don't taint the wonderful days of your new baby dealing with his shit.
Like I said, I don't think it's excusable EVER, but this is what he does when the going is "good". You know what he thinks is acceptable now. Staying with him will just reinforce that he can get away with it.
I'm sorry, it is awful. x