Bulky shoulders and neck from weights - How to reduce?

a strapless dress can look very nice on people who aren’t tall and thin

Fair enough @Pyri - probably a difference in tastes! I live near a Registry Office and I've seen too many hefty (not from muscles ) brides in strapless dresses, with flesh spilling over their backs and underarms. Not elegant ...

I did this when I fell in love with two weight machines at the gym. I was working one lot of muscles more than the others, 6 days a week, and felt like I’d started to get a ‘hump’. I mentioned it to one of the trainers and she gave me a more balanced routine that didn’t involve any machines. I think that the machines are just there to fill up floor space and lure the unwise.

I get the same way, I'm 5'3 and my upper body bulks quickly. I think people who say 'only 5kg' haven't seen how intense Caroline's workouts are.
I'd concentrate on Cardio and doing something like Tracy Anderson workouts 3 or 4 times a week. Her old mat workout is on youtube. She's a lunatic, and very boring, but her stuff does slim me down.

Put the weights down and go for a run instead.

I lift heavy and don't have muscle bulk like folk presume you get, I rarely do above 5 rep sets.

Sorry @LaChanticleer but a strapless dress can look very nice on people who aren’t tall and thin. A bolero or shrug is very very outdated now and would look worse than bare shoulders

Good that the advice here gives you something to go forward with OP.

Frankly, though, strapless dresses really are difficult to wear unless you're tall, thin, and either full chested, or very flat chested - they flatter very few people. I'm old-fashioned and find the apparently compulsory strapless wedding dress a big no no anyway.

Far more flattering, and showing off a lovely neckline, are dresses with sleeves but a broad low cut across shoulder & collar bone.

For example:
www.silkfred.com/womens/clothing/dresses/maxi-dresses/goddiva/bardot-pleated-occasion-maxi-dress-in-emerald-green?locale=en-GB&gclid=Cj0KCQiAxc6PBhCEARIsAH8Hff0WV0AeUmWj2oF6OlmTW1QS3Cyy8Yxxcr4n5F-1V-ABec4cFJt0koEaAkCuEALw_wcB

or
www.jjshouse.co.uk/A-Line-V-Neck-Asymmetrical-Satin-Mother-Of-The-Bride-Dress-With-Beading-Sequins-Pockets-008204918-g204918/?utm_term=204918&utm_size=06&gclid=Cj0KCQiAxc6PBhCEARIsAH8Hff3TGxUbMKK2_vc1Wjk5hwRjZ23aVhcOkF8tzYC-et_t52CrLw5SdL8aAugoEALw_wcB&ucid=3858

But I guess it's too late now ...

A lovely fitted shrug or bolero style jacket will do something to soften out the strapless look, and give you a more elegant line.

A couple of years and some health issues later I cannot do weights. I have been doing yoga for months and can see the difference in my muscle tone - yes I look more toned and stronger but it's a much more gentle shape and more forgiving and natural-looking if you have pockets of fat like I do.

So to sum up if you want to change the look of the neck / shoulder area for your wedding I would use yoga and pilates for your upper body.

Oh and to answer your question, don’t do exercises that work your traps. Make sure you don’t use your traps when eg you should be pulling your shoulder blades together. Just some thoughts.

If you’ve lost fat, then your upper traps (I think that’s what you’re referring to) might be more visible, especially if your collar bones are more pronounced now. Ditto if your bust and upper chest are leaner. So it might be your perception and your traps are just more toned.

Yeah I really don’t believe you’ve built muscle with 5kg weights. If you have co sister taking up and competing in bodybuilding, you’d be a natural.

Have you lost fat and the muscle is more obvious perhaps?

Would you be happy to share a picture? I'm sure you don't look bulky.

Would a shrug help you feel more comfortable?

I agree with comments above that 3-5kg isn’t enough to significantly build muscle esp on shoulders

More likely that your posture is affected or that you’re shrugging your shoulders too much on movements

I'm not sure a pirates instructor would be that helpful. Very difficult to find outside Dover.

There is no way you can have bulked that much with 3-5kg handweights, NO WAY, especially traps.

You're either the hulk's offspring or have some issues around body image.

Another one saying there is no way you would get that bulky with those weights. You have probably lost some weight and it’s just looking different to how it was. I’m sure you look fab.

Made, 5 kg is nothing

Pirates? Thanks for that my phone!

A concerted effort with a pirates instructor would help I think. I am tall, but broad and do a physical job. When I did alot of pirates, a couple of people described me as willowy.
Actually, an after thought, I have realpronounced shoulder/ neck muscles these days, it's from years of lifting small children with a core that doesn't work well due to diastasis recti. Basically all the effort goes through my upper back/ neck and jaw. I wonder if you haven't been using you core strength correctly during these workouts?

Try some ballet type exercises for arms. You never see a ballerina with big arms and shoulders. I think this happened to me ages ago from working on a rowing machine at the gym.

5 kg is a very modest weight, there is no way it could bulk you up.
I do think you are just seeing normal muscle definition being revealed, and being very critical because wedding dress etc. Try and focus on what you want to look like overall on your wedding day - no one is going to be focusing on your neck.

I'm sorry you are not happy with your results. But it is almost inconceivable that at that frequency and amount of weight you have bulked your muscle hugely more than it was already. As others have said, maybe you can see the muscle definition more if you have lost weight and if your midriff has got smaller then it will emphasise your shape.