I don’t understand

I need some help understanding something. I don’t really know what to google search but I thought y’all could help me. My and my bf have been having intercourse for quite a while. Over a year now and just last week he did something and I’m not sure what but everything became less tight and it’s been feeling a zillion times better than I thought it could. Could that be my hymen just now breaking? And if so how come it didn’t break sooner? I was really sore for a while and I got loved on a few hours ago and I was pretty sore too. It hurts a little bit when we do it now. I’m guessing I’m not used to this “new” thing