Rant/Advice/My boyfriend and his Scruff

[mataz]

So I know this topic has probably been discussed ad nauseam, however I need some individualized advice. Also I WOULD GO AND SPEAK TO HIM. However he is away on holiday and I don't want to ruin it for him. I would rather rant here and talk it out with someone.

BACKGROUND

So I have been going out with my boyfriend for almost two years now, things have been great (minor ups and down) but it's been awesome. He's my first ever boyfriend, I am 27 and he is 34. Mature, and has had strings of long term relationships (lasting 3-4 years previously).

Shortly after we both met we deleted grindr off our phone. A year ago though I saw he was chatting on this app called Scruff. I never had it, and apparently it was like grindr but worldwide. We talked about it, and he explained he never saw the harm in it, and it's similar to wanking to porn. I reiterated that I don't mind, however he felt he insisted he would delete it as he doesn't really care.

ISSUE

Fastforward a year from then and everything has been good, we live together. And there are no hints of him cheating and he seems 100% emotionally invested in the relationship. Offers me his free time first before planning things with friends, tries and coordinates days off to be together etc.

My phone broke though 3 days ago, and I went to the cupboard and used his old phone. I turn it on, and start getting scruff notifications. I OBVIOUSLY WASN'T INTENDING ON SPYING ON HIM OR BREACHING HIS PRIVACY. But it's hard to ignore and curiosity got the best of me.

So he clearly downloaded the app again, and has been using it. From the chats I can tell he's using it possibly once/twice a month. Mostly when I am on night shifts or on holiday. Looks like he uses it for wanking and sharing pics/videos.

He is open to them about 'living with his boy'. But once he talked to a man who doesnt have more pictures about how he can 'leave it for the real thing'. But ended it at that. And with another guy about how he should 'come for a weekend'.
One guy explicitly told my boyfriend that he might be hurting me by being so open on this app, he replied with:

"We talked about it, and he is fine with it, same as I would if he does the same. It's innocent and I don't like jealous people. (He mentions something about me being cute but not sporty). It's nice that you are so concerned but really it's ok. We don't do anything wrong it's like watching porn"

I have two problems with it:

1. He didn't tell me he is using it again.Even if I said I don't mind I should at least be entitled to this bit of information.

2. Also the content of the chats were quite disturbing. I assumed he would share cock pics and nude photos, but it seems like in his horny mood he talks about how he would like some guys "to come and fuck him on the beach". Followed by pictures of him on a nude beach. Or times where he tells them how perfect they are and how he would marry them.
He is sometimes very explicit and that's a side of him he doesn't show me when we have sex. (Obviously a bit jealous of that).

3. Also it's not like watching porn. I do watch porn when he's away and wank, but then mostly I fantasise about him, whilst with these apps it's making a connection with someone else. Do you guys think it's like watching porn?

Should I ruin a good relationship because of this? I feel like what we had was pure, but now it's tainted with this extra layer of complexity.

Damn technology. I am going to talk to him about it when he's back, but would like to hear what you guys have to say.