Wondering why I lasted so long

I have never been one to last long in bed with previous partners maybe 5-10 minutes tops but the first few times I had sex with my current gf I went around 45-50 minutes it felt great to not cum so fast for once we have much quicker rounds now back to how long I normally last my penis almost felt numb at the time just not sure if it was mental or because we switched positions a lot which is something I don’t do often but has anyone else had this happen to them?