Is it normal for people to pee outside here?

I’m 18 and in my second year of uni in the UK. I moved here when I was 15 and I come from a fairly conservative culture/background. But most of my mates are white/British. Because I was 17 during first year, I didn’t really go to many uni events, especially the drinking ones. This year we had our first big event and I offered to host pres at my house since I live at home and most people in my year live in student accommodation. About 40 guys came over. Around 15 were my actual friend group and the rest were friends of friends etc. We were all in the back garden drinking before heading out. People were loud, throwing drinks around a bit, shouting, which was honestly a bit rowdy but kind of what I expected. What surprised me though was I noticed groups of guys disappearing round the side of the house and coming back a few minutes later. Eventually I checked and they were literally just peeing in the bushes. I didn't say anything cos I was a bit awkward but it struck me as a bit odd. Then a little while later I went out to the front to grab something from my car. I saw three guys sitting on the front porch obviously quite drunk. One of them got up and just started peeing onto the lawn. Then while we were waiting for Ubers, a couple of them were peeing in the front garden in full view of everyone, including me, and nobody seemed bothered at all. Is this normal?