I have played casual with two others when i was with my old Master.. He enjoyed sharing me.. and you are right .. you still have to have trust and respect but you also need those times that you enjoy when you are sitting around after a play session.. I would spend a few days with these other Doms not just a few hours.. so we had to have a comman ground ..and things we enjoyed to do together..

I am still very close friends with the other two Dom's although we do not play any more.. and still enjoy their company and their humor and sharing things we both enjoy ..

As far as respect goes .. there has to be respect and concern for all parties or it is not much fun for either let alone the safety feature which is extremely important..

With both i had my saftey words .. they knew my limits and they took care of me even if i was ill.. as anyone concerned about a close friend would..Yes there were strong emotions and attachements.. but you have to have those to gain the trust that is needed even in a causal relationship.. just as you do with any close freindship..

I truly beleive it is wise to go slow and build on a D/s relationship... That way the trust is there as without it ..the relaxation and enjoyment can not be completely fufilled.. And it is harder to push limits and boundaries which you need to do to grow...

Just my opinion

hugs
snow