oh aye, it is tacky and an embarrassment, more so for some people than others. I find the Sun as a whole to be an embarrassment, along with a lot of stuff that passes for entertainment which I find crass, borderline offensive, lowest common denominator trash. But I'm not everyone else and it's not for me to dictate what constitutes acceptable level of taste for other people.
Breasts are great. No one is denying that. And women making a living in that industry is completely fine, if that's their choice. I don't think it's inherently sexist at all, generally speaking.
But none of that stops Page 3 from being a tacky, outdated embarrassment. In my opinion, obviously.
There's a time and a place. And in the context of a national newspaper, it seems completely out of place to me. Although classifying The Sun as a newspaper is a bit of a stretch.
And given that there's no Cock of the Day photo, you probably could make reasonable argument to suggest that it is a little bit sexist.