to feel unsettled after FIL returned late MIL's gifts?

Well done, OP, you are being helpful to FIL and it’s fine to have a grumble on here to people who don’t know your family and who therefore aren’t dealing with grief too

It is a common reaction to feel a strong and visceral need to find a “home” for the dead partner’s possessions. Its not rational but its entirely normal to want to keep as much of them in the world as possible. Of the estates/homes I’ve dealt with for spouses - two PiLs, two parents, a godmother and a couple of other elderly relatives - more than half felt this need to “rehome” possessions with friends, family or good causes.

Its not that long since the man was widowed. I would have (and have) rolled my eyes, gritted my teeth and got on with it because in terms of what the widow/widower needs it is what is most helfpul to them at the time. I didn’t realise just how strong and difficult that need could be until I was widowed and experienced it first hand, at which point I was genuinely glad I had just gritted my teeth and dealt with it and not told them to deal with their own shit.

Back to the OP’s question:
Or is this just one of those awkward grief things you just go along with?

Yes, its one of those things most people just go along with because it helps the family we (presumably) love. Its also fine to feel eye-rolly whilst you do it but I would still do it.

I'd just take all the clothes to the dump. They have clothing recycling bins, so shove it all in there.
Anything else your FIL brings that might be worth donating, by all means take to a charity shop, but they won't accept that much clothing in one go.
I got tons of stuff of my Aunts from my Uncle, he didn't want his sons or DILs to have it.🤦🏻‍♀️
It all went to the tip, because they will recycle as much as possible.

OP can be kind to her FIL and still feel put out by what he's doing. People are voting YABU because grief does funny things to people. So fair enough to be put out but keep it to yourself and help someone who is struggling.

Charity shops may have to pay to dispose of mildewed stuff, that should be going to a dump as you cant even recycle them.

So then nothing to feel put out about.

I’d take the clothes to a charity shop but keep the gifts for a while before asking anyone else in the family if they’d like them. If not you can then find other ways to part company with them. My daughters have the jewellery I gave to my mum as presents.

The poster above has made some very good suggestions. Not everything has to be dropped off at charity shops which can be pretty soulless places and nothing more than dumping grounds.

Hobby stuff donated to hobby group/club
Other gifts for school raffles
Bad condition clothes in bin.
Some clothes in supermarket recycling bins (usually found at the back of car parks).
Rest of clothes to charity shop, or refuge, or to a ‘back to work’ type organisation.
Coats gloves scarves to homeless shelter.

My MIL did this with FILs things, kept trying to pass things on. With her agreement we sold all his hobby stuff on eBay and split the proceeds between the grandchildren.

OP, the grieving brain is a funny old thing. My advice is to say to yourself, and really really really believe, that the ‘stuff’ will be useful to others and donate it all to Charity Shops, where it will do endless good.

No reason for you to go through them. You don’t want any of it so just leave it in bags and drop it off at charity.

If there is mildew they will deal with it.

This isn’t a huge burden but you’re acting like it is.

If any have mildew it would be better just putting the lot in a clothing bin

so sorry you’re having to do it OP, it’s a really crappy task, I know I’ve done it 3 times es 🤦‍♀️

Sounds like a way to deal with his grief. Maybe he can’t bear to throw them out but wants to clear out so by giving to you they’re not “gone” as such.

OP is entitled to her feelings.
Kindness goes both ways, the FIL is not being kind to OP and her husband in this situation. Her husband will be grieving too, and he is already dealing with the legal side.
Van loads of unwanted possessions with no value are not "a gift" in any sense.

I have unfortunately lost my DF and FIL in recent years and took on dealing with estates, funerals and other tasks but would have said no if either widow had just dropped a van load of clothes at my house without even discussing it first.

The OP doesn’t want these things. Doesn’t mean she doesn’t love or want to help her FIL.

Not at all. In fact, only when coming across posts like these, funnily enough.
I really don't think I'm the one being judgemental and thoughtless here. Maybe show your FIL the thread and see what he thinks?

And I'm the one that has no empathy?! OP has absolutely no thought for the FIL in all this at all. Just "put out" by the fact that he's 'dumping a load of old crap' onto her.
Just quietly pass it to a charity shop, you're obviously not going to use it. No need to make a thread about it, as all you've done is show yourself up as a person who clearly lacks compassion and thought. Have you always treated him with such irreverence?

This is pretty much exactly what most of us do/have done when an older family member dies.

Is it convenient? No, not least because its difficult for us as well but really its not as hard as being the spouse which utterly sucks. This isn’t some random stranger, he is their DF/FiL and sometimes we do shit for family because family.

Its not exactly something he will be doing again in a few months time - its a one off inconvenience. Just like arranging the funeral and dealing with the estate.

If it's helpful, some charities will pick up bags of clothes! E.g. Traid.

He may well be grieving, but piling a van full of stuff and dumping it on a relative is not sorting anything out. It's simply giving it to someone else. I've also unfortunately seen it happen when a man immediately has a new girlfriend and wants to rid himself of everything. Not suggesting that's the case here.