Yes, it's true, the word is AWFUL. Not in any way sexy, and I promise I will never use it in a fic.
But how do we feel about the practice? I'll give you a for instance.
Clark is fucking Lex. They're naked, in bed, sweaty, having the hottest sex EVER and it's so good and they want and love each other completely and when they fuck they really like it dirty and kinky and sometimes a little nasty. When Clark comes he's inside Lex and he's calling out Lex's name. Then afterwards, he covers Lex's body with kisses, he licks Lex's back, tasting sweat, tasting their mingled sweat, he moves down, and flicks his tongue between Lex's ass cheeks. He can taste himself. He likes it. Lex is moaning like crazy and it all feels natural and sexy. Then, and really, there's no nice way to put this, then he sucks his own come out of Lex's ass. The end.
Bonus points if you explain yourself in the comments.
More bonus points if you can rec me a (good, it must be good, I can't stress that enough) story where this happens. And it doesn't even have to be Smallville!