So sorry to hear this.
He will tell you that it installed without his knowledge and he just had a look. Or he saw an ad and looked because he was bored curious. Or it popped up and he was curious.
When you challenge that nonsense, he will tell you that a friend/colleague is on it and he did download it because he was curious. But he never messaged anyone and doesn't have an account.
When you challenge that, he will tell you that he only made an account because he needed to to have a look but didn't intend on using it.
When you challenge that, he will tell you that someone messaged him and he only replied to tell them he wasn't interested.
When you challenge that (because swiping), he will tell you that he did message but only to ask what it was all about and nothing was said or that he was looking for a harmless ego boost or that he was bored in lockdown and wanted some excitement. He will also tell you he had no intention of doing anything about it or leaving you.
Then, he may, or may not, finally admit to chatting/sexting/arranging to meet someone.
The script is well thumbed.
As for this... consider letting him live in his fantasy land. If it’s all tinder and porn then it’s not really different to me looking on rightmove at the million pound houses. it's very different.
Houses aren't people. I'd suggest this poster has either no experience of the current situation or is living it and this is how they rationalise it to themselves.