No, not those kinds of bears. I mean the other large, hairy mammals that run around shirtless:
This article reports the behaviors of two healthy male bears that were raised together at a sanctuary for brown bears in Kuterevo, Croatia. The authors speculate that the oral sex started as a nursing behavior, and the bears kept doing it because, well, it felt good.
NSFW photographs of hot bear-on-bear oral action can be found at Discover‘s Seriously, Science? blog.
Homosexual sex has been reported in every species, in the wild and in captivity, whose sexual behaviour has been studied, including Ford and Beach (1951). Now, however, the religious nuts will start blaming natural disasters on them.