Should I Let Him Know, I Know.

This isn't my confession really, it should be my husband's.

A few weeks ago a gay male colleague of mine showed me two videos he'd downloaded off a gay porn site.
Both videos showed a group of older men taking turns fucking a younger man.

One video was shot outside in some woods and three men were swapping between having their cocks sucked, fucking the younger guy, or taking over the filming.
The sex was very rough and the younger man was fucked extremely hard. But he seemed to want it that way.

The other video was taken in the lounge of one of the mens home.
There was five men this time sucking and fucking with the younger man, but also they were sexually interacting with each other as well.
It was a longer video around twelve minutes long, and it's very clear the younger man is definitely enjoying being fucked in lots of different positions.

The videos are dated around the same time three years ago. About four months before I met the younger man being fucked.
The same man I dated, got engaged to and married last summer.

Not once has my husband hinted about, or told me about his liking of gay sex and being fucked. However he does like me fingering his arsehole when he's fucking me missionary. He says he has a much stronger orgasm when he cums in me, which in turn makes me climax much more intensely.

My gay colleague knows my husband and instantly recognised him in the videos and that's why he showed them to me.

I'm not angry or hurt my husband enjoyed gay sex or being fucked before we even met, but I am a little confused why he didn't tell me anything.
Not because I'm annoyed about his secret, but because watching the videos these past few weeks over and over again, I've gotten incredibly turned on each time watching him take cock in his mouth and arsehole, and I've masturbated each time having amazing orgasms.

I'd love for my husband to know I've seen and thoroughly enjoyed the videos. I'd even possibly take part in a mmf threesome if he'd want to.
But I'm not sure how to raise the subject without making him feel bad or maybe even destroying our marriage. After all he hasn't said anything and with me he's such a manly man.