Why a whelk...

I can't really answer any of your questions, just give some of my own thoughts. I read a ton of TW fan fic and I've never read any slash before and I'm not a gay man. So I don't know about fan fic in other fandoms or the reality of gay male sex. But my own impression is that TW fan fic is overwhelmingly written by young straight women, some extremely young. So...there's that tendency towards romanticizing and heteronormative stuff and copying other fics. The stuff you're talking about doesn't bother me except for the scissoring thing, which sounds too clinical. If anything, there's too much lube, I agree. My main issue is that people put Jack and Ianto in some gay heaven where no one is homophobic and Ianto has absolutely no issues with being with a man (and usually people make Jack his first man - although my personal preference isn't that at all). I often wish there was some acknowledgement of reality on that front. I'd be curious as to how the depiction of the way they have sex compares to the reality of gay men.