Or over sensitive re comments about PT work?

I'd go a step further than mentioning your salary, and cheerfully encourage them to apply for part time hours too. Even better if they're young men without kids. "You should just go ahead and request part time Dan, you've been talking about it forever. It's painful when the pay comes in at the end of the month but it works for me, you might find it works for you too!"

I agree with the comments along the lines of 'remember, I get PT pay too'. I'd also be tempted to remind them that it's only because I worked hard, FT for many years first that enabled me to go PT now.

I had a couple of people react a bit like this when I was p/t. One said, ‘goodbye, part-timer’ one day as a kind of insult and I got a bit annoyed and said, ‘did you mean that to be an insult? Well done for knowing my contract’. I never got any more comments like that again.

I think if they are a bit jealous, try to just smile and ignore. Looking after pre-school children is not a day off but you don’t owe anyone an explanation or justification if they are being rude to you. I try and do the late Queen’s thing, ‘never complain, never explain’.

But sometimes that is not possible! You may decide to say, ‘yes, I am part-time in order to look after my children and my salary reflects that. ‘ if they keep going on and on but you really shouldn’t have to say anything. Last resort if it still continues, ask your HR to have a word.

I worked part time for many years. But I also found people who mentioned unavailability due to PT or only working x days on a regular basis annoying. I just used to say yes I can or no I can't without adding on why. You have to be more confident about what you are doing. I don't think it helps to say everyone can work PT because it's not true if you can not afford it. Also coming back from Mat leave you can negotiate your days, if not in my place of work you'd have to apply. I always tried to offer to do extra when I could , when my husband collected children so on the days I had no flexibility I felt OK about not being able to help. Don't apologise for working part time but also cut full timers some slack as that isn't easy either.

When I worked PT, I found I ended up still having a FT workload but with less pay and less time to get stuff done. I've since gone back to FT, because stuff that - post Covid and a more flexible employer do mean I can WFH a lot (ditto DH) which means school pick-ups/ drop-off can be more easily handled.

If OP is getting lots of nasty, hostile comments it may be worth noting it with their boss/ HR. No need to say anything more directly if people are being openly hostile.

I think some people might be bitter because they couldn't afford to do go part time? Do they feel like there is a cost to them of others being part time? I would have liked to go part time before I did though didn't begrudge those who could. Others are just prats.

I used to get the same and comments about my days off like I was on holiday every week. On my two days 'off' I had my young DC and my doubly incontinent, memory impaired mother to look after. On the flip side I did feel like I was coming back to work every week after being on holiday and having to catch up which wasn't nice either.

I said this and instantly got the response 'you can't have it both ways!'

Yes I know dickhead, but I wasn't the one complaining about it!

I wouldn't say you are 'lucky' to be working part time. I work part time and if anyone says that to me I just say 'not so lucky when the wages come in'. I don't care what anyone else thinks though, you do what's right for you and your family. My kids are all at school now and I have no intentions of going full time yet, feel like I am finally getting some time to myself after 10 years of having young kids at home so will enjoy it (probably until my fixed
mortgage rate ends 🙈).

I used to work with a few horrible bitchy women who would make comments about my part time work. I tried stating I only received half pay, I was busy with small children etc.
In the end I got so fed up I'd just breeze out and when they started bitching say "Oh I know, part time reeeeaaally is the best, you should try it!".
They were bitter bitches, there was no way to win them round.

I have had similar in the past. I shut it down by saying 'you do realise that I get paid a part time wage'. As far as I was concerned I was no 'luckier' than my colleagues.

I am also part time - 0.5 FTE. I often get comments on it too, esp now my kids are teenagers and mostly self reliant.

To snarky comments about how lucky I am, I say "Don't forget I only get half the pay"

I don't see what you'd achieve by saying anything - just sounds like they're rather jealous. I'd just ignore it personally and think, yeah, I am indeed lucky :)