Watching the first time

I like the "idea" of this, but why is it that guys like the idea of this also?
I think most guys just want to watch their wife/girlfriend get a good fucking from a well-hung guy at least once, just to see if she really does cum harder and more often when her pussy is full to the brim, I remember the first time I bought a guy with a huge dick home and let my then boyfriend watch him fuck me, I was moaning and cuming my little pussy off, like I always do with a hung guy, when it was all over and I was a quivering mess on the bed and the guy had left, my boyfriend said I would never have believed your pussy could have taken a cock that size to the balls like you just did. He was shocked that I was begging a guy with a cock that size to fuck me harder and deeper, and that I was rubbing my clit, rubbing and pinching my nipples while this guy fucked me, my boyfriend was thrilled to see this other guy bring out the horny little slut in my, then I was almost shocked when he said now I have seen for myself why women all say bigger is better.