Don't know about him going down on a guy but a guy going down on him. Definitely appealing. A cock that lovely needs some extra worship.
This is not something I would want to happen....
It happens very very occasionally with our FWB boys mainly if its MMF.
Its not popular and it only happens in the heat of the moment and never for more than a minute.
It does not bother me they do it but I say its not for me - heat of the moment or not.
I tend to gravitate to bisexual guys, or guys that are at least curious, and not overtly homophobic. So I've been in a couple MFM threesomes where I got my 2 male partners to blow each other. It was hot!
Wife has set this up a few times, she loves it...
it's a fantasy, luv to be with a man that was that open and self confident