How to stop annoying soothing habit in toddler

[MsAmbivalence]

I've signed up to Mumsnet because I'm desperate for advice on this.
My son has just turned three, and has a habit of 'stroking' (often pinching/tweaking) his parents' skin. His preference is elbows, and whenever he sits with us, the first thing he does is put his hands up our sleeves. If he can't get to elbows, however, it's any skin he can get his hands on (waist, neck, face... anything).
He was breastfed until he was just over two years old, and had a very strong sleep association with breastfeeding. I'm certain this comfort-habit is associated with his sleep association, because he makes a suckling motion while he's doing it. He started doing it about five or six months ago, and at first we ignored it...
He has never been a good sleeper, and tends to fall asleep doing this. Then when he wakes in the night, he does it again in order to get back to sleep. (He's in his own bed at night, but will come and find us if he wakes up). If he has a restless night, he will literally do this all night long.
I know it doesn't sound like a big deal, but it is driving us to distraction. Six months of pinching and tweaking drives you mad. I actually feel like I'm getting less sleep now than when he was a tiny baby, due to this habit.
We have tried explaining that Mummy and Daddy simply don't like it. (I'm not even sure he's doing it consciously, so this hasn't helped).
We have tried giving him something else to stroke, but he has no interest in toys or replacements - it's got to be skin.
I've tried making skin inaccessible, but even the unflattering onesie hasn't helped. He'll just spend his time trying to find access, which is almost more distracting than the stroking itself. We end up literally fighting him off.
We've tried replacing with hugs and hand-holding. I don't mind body contact in the slightest, but he just can't keep still, it always descends into the stroking/pinching.
I'm sure this all sounds really silly, but we really need to wean him off this habit, as it's not only annoying, it's really starting to affect me because I'm so tired. I worry that it's a fairly antisocial habit too, as I'm not sure he doesn't try it with other adults, too.
HELP!

distraction when he does it?

DD2 did something similar by putting her hands down my top. I used to take them out and say a very firm no. It took 6 months, but eventually she started stuffing her hand down her own top and stroking her own collar bone instead. Which looks quite cute!

I think your biggest issue is that he's using it to go to sleep. I think you're going to have to break that association before you get anywhere with anything else. You might want to get over to the sleep boards for suggestions.

You have to be firm, compassionate and consistent and say "no, I don't like that" loudly and remove his hand again and again and again.

if he continues tell him that you do t want to sit next to him, and move.

You do need to get this under control before school.

Get him a pet?

You've got all my sympathy MsAmbivalence!

My DD 20months has slipped into a similar obsessive habit of sticking her hand down my top and squeezing my boobs and fiddling with nipple. It varies from irritating to really painful, and I often have scratches down my neck. She does it numerous times a day, at bedtime, and then a lot during the night (she's in our bed from about midnight). It's definitely a substitute from breastfeeding - she only gets a bedtime feed now, and it started after I weaned her at night. She does the same sucking movement with her mouth as you describe, and dribbles and goes off into a trance... I think toddlers who were breastfed a long time must just be used to a lot of physical contact and they clearly feel it intensely when the breast goes.

I tried saying no solidly for a month and taking her hand out, and it caused us both so much angst that I went back. Wearing polo neck tops made no difference.

How on earth to fix it at nighttime?

My Ds does this but pinches and tweeks my face. He also nuzzles my face and looks like he's trying to suckle it. Drives me potty and he has been doing this for about a year now. If he wakes early and comes in my bed he does this all night and I get no sleep. It's starting to get irritating.

I'm still not really any further on with this. We are still just saying 'no' and constantly reminding him that we don't like it. I will often tell him that if he doesn't stop, I'm going to get up and go away from him. It does work by day, and I think he does understand that it's unwanted attention, but the more tired he is, the more unconscious I think the action is, so we still haven't won the battle, it's like a deeply ingrained habit that he'll keep going back to.
djwholesome, if he could, I've no doubt that the skin he's really after is boobs! When I first stopped breastfeeding, he was the same - hands down top, etc. He seemed to accept my explanation that he was too old for boobs (I didn't want to stigmatise it, but I equally didn't want him doing that all the time). I thought he'd accepted and moved on, but then he replaced boobs with any skin he could get his hands on, and we haven't got past that!
I suppose they aren't little forever, but these habits are really annoying, aren't they?!

My 5 year old is the same. Has to twiddle and stroke ears and face. Has never grown out of it but it is now time restricted. Not during day unless 5-10 mins watching TV if very tired. Not in middle of night until alarm clock goes off. It drives me insane

DixieNormas, when I weaned my two year old off breast-feeding, we replaced night time feed with a cuddle and a lullaby. In the run-up to stopping BF, I had explained to him several times that he would soon be 'grown up' and would need to stop, and I explained to him when it was his last feed. We also symbolically removed the nursing chair from his bedroom and put it downstairs. I went away for a few days after my last feed (I had to go away with work, so we used this break to coincide with stopping BF). When I returned, I still put him to bed, still gave him a cuddle, but replaced the feed with a lullaby. Because we'd given him lots of warning, he seemed to accept this...
However, he has ultimately developed the stroking habit as a BF replacement, so I would say if your LO starts doing anything that might descend into an annoying habit, nip it in the bud early! Good luck, it isn't always easy.