Did That Really Happen?

Married. 34. Straight.
So why did I have a crazy urge to let him fuck me?
I saw him at the pool bar with his female partner. He was in very brief speedos and when he stood to go to the bathroom , I looked at his body and huge bulge and got an erection.
I had a towel around my waist over my own speedos so was able to conceal my erect cock.
I followed him to the male spa and watched him go into a toilet cubicle. I heard him flush and watched him wash his hands in the basin.
I was still fully erect. My cock had pushed up and most of it was visible above my speedo waist tie.
I let my towel fall to the floor and just stood looking at him.
He smiled and walked to the sauna, looking back at me as he pulled the door open.
I followed him and by the time I walked in to the sauna he was nude and fully erect
We didn't speak.
He kissed me and pushed my head down so he could push his cock into my mouth.
A cock in my fucking mouth?
I loved it...sucking and kissing it...licking the thick shaft.
He then simply said I am going to fuck your hot ass...and did just that.
It hurt. It really fucking hurt. Then once he was deep inside me, it started to feel good. Really fucking good.
He moaned and groaned and after about 10 minutes of so his body shuddered and he ejaculated in me.
He pulled out and pulled on his speedos and walked out
I masturbated, ejaculated and did the same.
WTF?