Is this a red flag?

[Elmo290]

I've been with my current partner for a year but we have been friends for 12 years although we did lose touch for a while in real life but did wish each other happy birthday on Fbook etc.
This evening we've had a conversation regarding strip clubs ,stag dos etc and he said he had a private dance whilst single but wouldn't do it in a relationship.
Then later on he said that he had private dances once or twice a month for around a year ( around 5 years ago) when his marriage ended. This went on for about 18 months and then stopped
I'm actually shocked as I didn't think this was what he was into at all.
He's said he was single and he wasn't doing anything wrong. I had no idea he was into this sort of thing.
Am I overthinking?
TIA

For context it gives me the ick as he was in his early forties then

Yeah. I’d be put off too, personally. The second time around was quite a regular basis too. The fact he took a year to reveal that while you are at the dating stage does make me wonder if it also sometimes happened in his marriage too but not yet revealed.
And the fact you have been friends for 12 years and are surprised by the revelation seems to indicate he has parts of himself he keeps hidden and therefore that suggests you would need a long time to really get to know him in the dating stage.

Yeah he's never mentioned it at all even when friends so I'm a bit shocked.

Well he views women as sex objects.
He pervs over young women half his age.
He is giving you a drip feed - what other revelations is he going to come out with.
If going to strip clubs and having private dances is normal behaviour for him he will continue to do it.
I wouldn't want to be with a man who buys women in this way.

Something like this would fundamentally change how I felt about a person. It indicates an attitude to women which I find deeply unattractive to the point where it would outweigh everything else I felt about that person. Only you know how you feel OP but don't let anyone tell you that you're overreacting or 'all men do it', you're not and they don't and if you feel strongly enough to end the relationship over this then that's absolutely ok.