Confused feelings for friend/fwb

I've been friends with this guy for about 4 years now. We climb together so we have a super solid bond and we kind of just 'fit'. We can be together all day, all night and not get sick of each other. The problem is we've started easing into being fwbs but I CANNOT get past the fact that every time I look at him when we're in bed together, I see my goofy buddy and not a romantic partner. I haven't been able to reconcile this dichotomy and it's why we haven't slept together. We have fooled around but that's it.

When push comes to shove I find it so hard to flip the switch and see him in a romantic light as a sexual partner. He is also not my type AT ALL which doesn't help, but I know if I let my guard down we would be a great couple. In my head I think, "this is your friend, what are you doing?!" He knows all of this too btw, we've talked about it and for now he is being patient. I just don't know how to reconcile this, if it even can be done.

Has anyone been in a similar situation before?