To ask my neighbours to tone it down?

[Sunflower20]

New neighbours have moved into the flat above me and they keep having sex at odd hours. I never hear anything vocal, just rhythmic thumping which goes through my ceiling. I've been woken up a few times now. This is not just on the weekend either - I was woken up by my ceiling thumping to the point of breaking at around 3:40am last week during a weekday, and this went on until about 4:20am. The other day it was 2am, and this morning again at almost 5am!
WHO DOES THAT!!!!
I've heard them a couple of times during the day as well but I guess that's fine.
I'm not a confrontational person, and I get that people can have sex whenever they want, but surely this is ridiculous?! Who the fuck has sex at 4am on a regular basis!? I thought it would be a one off but doesn't look like it so far.

Should I speak to them face to face or write a note and what should I even say? I'm not really a confrontational person and find this highly uncomfortable, what if they tell me to fuck off and do it even more?

I don't sleep well anyway and this isn't helping.

I'd write a lighthearted note just asking them to keep the banging to a minimum

I don't think it's particularly odd tbh.

The noise is not ok if it's causing you to lose sleep though.

Stick a note through the door.
Happy to hear your sexlife is alive and well. However It is very loud and waking us at all hours. Please keep it down.

What if they arent having sex though?

Ok I'll write a note but if it happens again I'm guessing it wouldn't be entirely unreasonable for me to go up and knock on the door, at the time?

I had new neighbours earlier in the year who started having screaming arguments at 3/4am so waking me up, it was him going out after an argument early evening then coming in drunk, first couple of times I gave benefit of the doubt but I was struggling st work with tiredness so left a note, next time I rang the letting agency who said they had several complaints and the couple were splitting up and one moving out, was a few months of hell, barely hear a peep from next door now

Don’t be explicit about it if you don’t want to embarrass them/ sour the relationship. Just a simple ‘we are being disturbed by noise in the middle of the night, could you try to keep it down as the soundproofing between flats isn’t great. Thanks’

Put some loud music on next time they start up. They’ll hopefully get the hint.

@IVEgottheDECAF
See I've thought about this, which is why I haven't said anything yet.
Could be exercising I guess? I'm not 100% sure but that would just be strange.
So surely they're having sex!?

DB runs before work and does weird shifts (travel industry) so he will sometimes be waking up for the day at 3am having a run, and going to work for 6am or waking for the day at 2pm, running, and away to start the work day at 5pm.

I reckon it's a treadmill rather than shagging.

This reminds me of the Gavin and Stacey episode where they turned the radio on to drown the noise - Barry Manilow singing "Come, come, come into my arms".