@ProbablyNutsTBH I hope you did not use the voucher yet.
I would argue you have two options if you don't want to cause drama:
- Accept the gift as it is and that's it
- Accept the gift but make clear they don't need to babysit your DS cause you want him to be with you and your DH
I do feel maybe you're reading a little too much into their intent and they're just typical overbearing GP because they're excited for having a GS, but fact is even if there's no malicious intent they still gave a gift with strings attached, unlike what some seem to think a real gift don't have any strings attached, so I think it's valid you have mixed feelings over it, but it's quite possible or even likely they don't realize how it looks and you can't help but see it more negative than it is due to them being overbearing.
From what you said you don't necessarely dislike your PIL, you simply find them overbearing at times, my suggestion is that you build boundaries and keep them, a perfect example of that is how your PIL keep sending you messages that are for your DH, they don't even send message for you to tell him something, it's outright message for him and completely ignores you, never let that happen again, you're not your husband secretary, ignore or even delete those messages if they don't stop.
Maybe you should try have more of a routine with them, like every Saturday take your DS to see them, like that they won't need to keep bothering you about seeing their GS nor send a bunch of messages asking about it, though I feel you would need to do the same for your parents too so both sides are happy.
My suggestion is to accept the gift and make it a family dinner, it's your gift after all, so you decide how to use it, they might get sad and disappointed but such is life, but if they get defensive or even confrontational then you have your proof that it was purposely underhanded and manipulative tact from them to have your GS for themselves all day.
I also suggest you ignore all the backlash you're getting here, yeah it's sad that some people can't be part of their GC life for some reason, some don't have PIL in their DC life, or that they get no support at all, but that is their problem, they don't get to project their bitterness on your or judge you because you want to do what is best for you and your family, you said yourself that, you don't need a break from your son, the fact that so many ignore that and attack you because you dare to not want to separate from your son proves that a lot of the attack is done in bad faith, the fact that they clearly hope you suffer what they suffer when you have GC is more than enough proof that all their attack is done out of malice and bitterness, it oozes from them.
I want to repeat you need to build boundaries, boundaries are healthy, boundaries are good, it's your son, you get to decide how and when your PIL see them, it has to be on your terms, not theirs, you're only thinking of now but you need to remember this will keep happening until DS is an adult and move to build his own life, if you don't take control of the situation it will only get worse as he grows old cause they'll want more and more time with him, which is not bad, but they can't be the ones in control, you and DH are the ones that need to be in control, it's literally your duty as parents.
Build boundaries and don't give in, you're already getting tired and stressed with them being overbearing, it will only get worse in the long run, you'll start to feel bitter about them being overbearing, your negative feelings for them will only get worse unless you change things.
Take control of things now before someone feelings really get hurt, your PIL are adults so treat them like adults, no is a complete sentence as they say, you said before that you and DH had the “we’re responsible for our own family’s” talk 50 times and eventually you give in, if you can't have a firm hand and have boundaries with your PIL how will you be able to have it with your DS when he's older? If DS keeps forcing on something he wants will you eventually give in just like you did for his GP? And what if PIL spoil him too much and he starts thinking he can do anything and everything he wants cause they spoiled him rotten?
Maybe buy yourself a spine as birthday gift and stop giving in after building boundaries.
Build boundaries, they're healthy and good for everyone involved, mentally and emotionally, do that now while DS is young before things really get out of control.
Sorry the rant (ノ´д`)