Morning All and Happy Mothers Day 
I need some advice.....we live in a flat, there's a flat downstairs and ours. A young couple (20s) live downstairs with their boys 4 and 1. The bloke has is a shouter and would appear to have some serious anger issues. At approx 2.30am I woke up to their flat door slamming and walls being kicked or punched and him shouting at her. I can't work out whether he'd come in from a night out or they'd both come in together. Anyhow he was shouting and saying you made me walk home, look at my shit, do you think I'm a dickhead, a dickhead etc really shouting at the top of his voice, he continued to bang walls etc. I couldn't hear her at all. The kids weren't there (well I didn't hear them wake up, which I think they would have done) My pulse was racing and I was scared for her. I came so close to calling the police. I didn't because it would be obvious that it was me and I have to live here long term, they're tenants, I own my flat. But I think I should have. He is always shouting at the kids, not just a telling off, but a full on face rattle shouting. She's recently gone back to work in London. She leaves early on a Monday morning and comes back on Thursday late evening. He looks after the kids when she's away. I don't think she realises how much he shouts at the kids. I feel very torn and as I'm typing this my pulse is pumping fast like it was last night. I feel very torn by it all, on the one hand I don't want to get involved (not my circus not my monkeys) but on the other, if anything happens to her, I will never forgive myself. It's like he has 'a switch' that flips. I have heard other arguments over the year that they've been here and it's always putting her down, demeaning comments etc.
What do you think I should do? I don't think they realise quite how clearly we can hear from our flat. I couldn't get back to sleep for ages. Your wise views please x
DD2 has a regional tumble competition today - so glad it wasn't this morning, they had to be there at 7am, she has to be there for 2.30, not competing until 5.30, presentations at 7.30, so late on a frigging school night 
Sorry for my 'me' post. Have a good day, the sun is shining 