To just want to go home after work?

Make it about what is best for your son.
Create a plan.
Invite your folks over for a meal one night per week, you eat at theirs another two nights and keep your son's bedtime at a similar time, having completed his homework etc..
A set plan will make meal times predictable; your parents will know in advance when you are staying and they'll be able to have an earlier meal. Asking and you sometimes eating there and sometimes not is not the best for your child's bedtime.
Would leaving your son to be taken to school a couple of set days per week by your parents be workable?
(Then two nights per week you are picking him up and going straight home.)

I was the child in this caae in the 1980s. My mother would collect me from my grandmother's and sit down chatting for half an hour. This was from primary right up til I was finishing secondary. We lived out the country so I walked from school to their house and got collected at 5 pm. It was often 6.30pm by the time we got home.

Worse when I was teens as I had lots of homework and was up til 10pm and later doing it. My mother kept chatting about nothing. Even when I told my grandmother she tried to curtail the chatting. Thrn my mother would try to chat to me on the way home and got VERY offended when I said I was tired.

Some people just DON'T CARE. Your mother is suiting herself and using you for company, just like my mother kept bringing us home late and chatting.

that was in response to when they do offer to cook, cooking is not started till op arrives at house which I thought strange as I wouldn't do that I would have it ready to serve when op arrives
op says that parents are asking not she asking!!!

This happened to me, my Mum and Dad would look after them after school at my house but then stay and chat after I arrived home for an hour plus and I used to be almost crying, overstimulated, needing to start dinner etc but I guess it’s the price you pay for free childcare. I do wish parents were more understanding of this though tbh, I’d like to think I would be and just have a quick chat and get off. I never solved the problem FYI. I just paid for childcare and reduced my hours which is obviously not great.

I’d say that it’s a long time for you to be out of the house, 8-8 sometimes, and it means it’s difficult for you to manage what you need to do at home in that time - get a wash on, make packed lunches etc, get a decent nights sleep - also a very long day for your child. Could you stay on a Friday evening for dinner, when you can relax properly and not be watching the clock/worrying about the next day.

If work would find it hard to let you reduce your hours right now, could you maybe work half an hour less on the three ASC days, then 45 mins more on the two other days? That way you would be working the same hours in total.

Can’t you find a childcare arrangement where someone takes DS home to chill in your own home after school a couple of days a week? Then you can go straight home to relieve the babysitter/minder your parents etc.

I'd try to arrange to be able to pick your ds up on the after school club nights. Then maybe stay half hour on the days you pick him up from theirs.

I'd explain it's late and ds needs to get ready for bed.

This is a tricky one. It’s nice that she wants to spend time with you but she’s so clearly not considering the context of your day and needs at all.
One night would be fine (and surely having dinner ready isn’t a huge ask given that they’re making it for you anyway and not starting until late makes it a very late night for your son). But beyond that it is her being a bit selfish and thoughtless. As you say, she didn’t work until you were already pretty independent in secondary school, and always had a partner to share the load. Totally different to having a primary aged child and also parenting solo whilst working full time. Can she not appreciate that?
You’ll need to be honest but she may take it poorly. They did volunteer but the help is only helpful if it’s not tied in with so much guilt and lots of conditions that actually erode your tiny amount of free time to manage your own life and throw your routine out. I have entirely reduced my parents’ involvement because of all the emotional manipulation inherent in any “favours”. Hopefully you get a better outcome following a chat to clear the air and establish new boundaries.

This.Plus DC's bedtime is being pushed back an hour, surely. There just isn't time!

I think it's being astonishingly thick to not understand that someone who has been at work for 8 hours likely wants to get home and has evening tasks to complete with and for a child before bed.

Honesty is always the way to go. Sit down and explain to your DM that by the time you are done with work you're tired and you just want to be able to go home. Maybe compromise by continuing to have dinner with them one night and take them out sometimes on a weekend for lunch or brunch. If it continues to be an issue after discussing it, you may need to make other arrangements for childcare. Good Luck

I think your dm is being incredibly unreasonable & im shocked people in this thread can’t see this. You’re a single and working parent life is bloody hard and yes after a long working day you are exhausted and want to just get home. I feel you. If you are seeing your parents to catch up at least once a fortnight or week or whatever that’s the time to catch up with them properly- not on collection of dc after a gruelling day. As if she got angry- she has zero insight & empathy here but I’ll be honest rather that the whining out of supposed earshot that you what to gooooo hommme which is pretty passive & childlike I would sit her down say on a weekend and say explicitly that you love their company and massively appreciate their help but please understand I want to get home after work and get x y z done and unwind etc but will catch up properly and regularly another time when you’ve got the time ie weekend. I’m in a very similar situation and my dm would totally understand this because I see her every other weekend & call/text in the week. If you just communicate carefully that’s the way forward. If dm still is unreasonable then it’s time to reconsider childcare/working pattern.

So in addition to five days a week of school runs and after school care, the retired parents should now also be free cooks for the OP?

It blows my mind that people have this level of support from their parents/in laws.

I would have killed to have this arrangement. I had no offer of childcare for dc. Never. Not once.

I know how hard it is being a lone parent op but your parents sound wonderful honestly.

I think I would be pretty hurt to hear my daughter whine “I want to go home”. I understand why you might want to but that was rude and childish in the extreme. You need to have an honest conversation with your mum, apologise for whining but explain that you are knackered and have such a short one on one time with your DS in the evenings you are struggling to get home so late. Maybe plan one night a week when you stay for dinner/a cuppa and a chat. When DIL collects her daughter who we look after 6.45am-4.45pm one day a week I would love to hand her over at the door tbh as I am exhausted too but we play the polite game and keep it to 5-10 minutes.

I think DM is really helping out and I would take full advantage. It sounds like you could enjoy a nice dinner a couple of times a week with DS and parents. Then you can head home and not worry about dinner! It would save time and money.

And how many years left until DS is home by himself and doesn’t need babysitting? Maybe five years and between then and now anything can change.

I wouldn’t talk about it you may end up upsetting DM and then upsetting the arrangement. It’s a really great set up.

I'm with @ManukaNourished and I'm the grandparent. We love the little ones but three days a week would strain my husbands patience especially if he had to be sociable too.

Tactfully tell your mum that your employer has adjusted staff hours.

If by some miracle you could get alternative childcare until 6.30pm, how would your mum react? Would she be pleased or very disappointed?
I think the answer to that informs how guilty you should feel about going straight home. If she is delighted to be relieved of childcare then you definitely need to approach using kid gloves

if she would be upset then this is an arrangement that works for her too, and I would be feeling more confident setting a limit. Especially since you spend a good portion of you weekend with them.

fwiw I would go down the path of least resistance and spend a lot of time complaining how tired I was in the hope they take the hint, and arrange to have tea with them so she knpws
to get it started before you arrive.

Every day?? When you still have to do tea, homework, bath and bed? And every other weekend??

As the mum/GM in question I wouldn't want that either!

Yanbu, my gran never expected this from my mum and neither did my mum from me, they could understand after a days work why I’d want to get home, parents help usually doesn’t come with conditions, especially when you have dinner once per week and see them at weekends, it’s quite selfish actually and not good for your son

I don’t understand the comments on this at all.

Your DP are doing you a favour, yes but you shouldn’t feel obliged to stay because of this, maybe once a week max stay for dinner or order a takeaway but there really should be no need for you to feel this way, you could arrange to spend quality time together on a weekend instead. Please just talk to her and explain how you feel, you shouldn’t have to get home at 8pm as by that time you’ll have to put your DS to bed and you won’t have any time to yourself until after 9pm most likely!

My parents help me out loads but they are never bothered about me staying when I pick the kids up, in fact it’s more the other way around and they can’t wait to get rid of us 😂

Oh this all sounds so tiring. I would really struggle with that too OP... and it's absolutely no reflection of how much you love them

YANBU but DM is being quite selfish. I hope you find a way to convey that without upsetting her.

Oh OP you must be shattered. Of course it’s nice of your parents but it’s not like they never see you!

I agree with others, just set a weekly evening to stay for dinner, and leave quickly the other times. Just be honest and say you have tons to do when you get back and you look forward to catching up with them properly on x day.