Is Following Sexual Instagram Accounts Questionable For A Committed Relationship?

So this may sound very naive but I'm genuinely curious and do not want to come across as prude or controlling in a new relationship so I'm hoping for a male perspective, but am open to any advice or insight.

I (27F) was in a 6 year relationship with a (30M) man who blindsided me with cheating. I later found multiple things he had been hiding but one of the more "tame" indiscretions was that he followed 40+ soft core, lingerie, and just random 19-23 year old girls Instagram accounts. I knew he watched porn and looked at provocative pictures and I never once had a jealous bone about it. Occasionally we would enjoy porn together and I was very open sexually. I wasn't one to cyber stalk my BF or monitor activity so it never crossed my mind until I found out about his infidelity and then started snooping. I hated it. I have never had the urge to check up on an SO because I trusted them and this felt like an all time low for me.

After the cheating incident and a failed attempt at reconciliation I was trying to evaluate red flags I had missed and what was just "guy behavior". Part of me believes that this questioning is all in part due to the cheating. I never would have cared or even thought about this in our relationship before the incident but now I'm worried I was maybe too naive and this should have been a HUGE red flag that I missed and should have cared about.

From a male perspective (or anyone who has been in a similar situation), is it typical to openly follow provocative sites like this that all your followers can potentially see? I have been looking online for other people's thoughts and it's such a broad response. Some people find it ok, not ok, depends on the guys age, his maturity level, etc.

I hope I'm not offending anyone or trivializing something that other people find sexually enjoyable...I'm just very confused and I think clouded by infidelity insecurity that I'm having trouble accepting some acts that in the past never would have bothered me as a woman secure in a relationship with her man that I now look at more critically.

Thanks for any insight!

TL;DR I was cheated on in a 6 year relationship and am now insecure about certain sexual things via social media that wouldn't have bothered me in the past. Is being concerned about your SO following sexual social media accounts ridiculous?