Help to save marriage from ruin

Hubs and I have been together since our teens. Weve had our ups and downs but made it through together. Weve got beautiful kids and work hard for what we have. He works DIDO 7/7 and always has during our relationship.
Theres been 2 occasions about 10 years ago where i found out he was calling "adult" numbers. We did marriage counselling back then (biggest waste of money there, we sort of worked it out ourselves). All was left in the past...so I thought.
I have recently found d*** pics on his phone including "front and back areas". Occasionally we might send "spicy" pics to each other but he didnt send these to me and they were a bit odd (only the private parts, no body/face in them).
Futher searching led me to find call logs and when googling the phone numbers, they are of the personal classified genre, both females AND males! Hubs lost his virg*nity to me so hes never "explored" anything else.
Alot of the calls last for only a second so they mustnt have answered but there were a couple that were around 3-5 minutes then a couple that were around 20 minutes. I dont have access to his phone records (long story, not his choice or mine) but seeing these few make me feel just ick!
Do I confront him? How do I solve this? Im not ready to call it quits, i get that you have to work to make a marriage work. I just dont know how to do this without either blowing it up and having it break down or having it swept under the carpet like all those years ago.