As other posters have said, Occams Razor - simplest explanation is the most likely.
Only you know if he’s the type of clean freak who would wank with a condom on OP. You know he has no reason to use them with you, so it’s unlikely he would actually buy them just for the purpose of a ‘posh wank’.
Would he actually bother to get into bed in the daytime to do that anyway? May as well sit on sofa or at his work station seeing as he’s gone to the trouble of ensuring no mess by buying condoms for that specific purpose.
An unlikely scenario IMO.
He could have had someone in and had sex on top of the quilt or the bed spread (do you have one), even on top of a towel as he would obviously be aware it’s his wife’s bed (!) and you may notice hairs or smells. They didn’t need to get into bed for sex in the day and most people wouldn’t. DH and I don’t!
He could have washed the quilt cover or bed cover or even just shaken it and not noticed a bit of the condom wrapper had flown into the bed when he shook it out.
How likely is it he could get someone into your house undetected by nosy neighbours OP? We have a driveway shielded from the road by a hedge and no one directly opposite for example. Back gate access etc?
I’d work on the assumption he had reason to use a condom while in the vicinity of your bed in your bedroom and it wasn’t for sex with you.
I’d be popping back home at lunchtime next week, parking up the road and extremely quietly entering the house on the day of the week you found the wrapper OP.
Tomorrow or tonight even say you’re ordering a doorbell camera from Amazon (decent ones for £40) as you’ve heard there’s been break ins in the area and see what he says. You will know if it’s been turned off from the app it will be on. Don’t push it if he fights against one.
You could still get one and position it secretly outside, in a hedge temporarily?, as long as it’s positioned to pick up the frontage of house and can pick up the house WiFi signal.
I certainly wouldn’t expect a truthful answer from a possible cheating husband so I would avoid asking him outright until you’re sure there is no other evidence because he’ll make sure there won’t be if you let him know you’re suspicious. I wouldn’t be able to hold it in for long though (a week tops) so try to do some digging as well without alerting him.
There’s no way I’d miss the opportunity to get the truth by warning him that I was looking for it.
Check his side of the wardrobe as well as you may find the rest of his condom stash. Car. garage, coat pockets, gym/work bags, phone if you can get into it.
Has he been anywhere abroad recently which would explain the foreign language on the wrapper?