It's not them, just some random gay erotica photo. It sure does look like them though. The stupid-ass haircut on the one in front (Krycek), the line of the other guy's jaw (Mulder).

The only time they ever kissed on the show was at the end of "The Red and the Black," when Krycek kissed Mulder in his apartment. But it wasn't a full-body press against the wall like this.

Those were the days, man. :-D I miss those guys.