who to choose...when both boys want to do something different?

My husband had eye surgery today, so the boys spent the night at Grammy's.  After I got my husband settled in bed to rest, I went to retrieve the boys from my parents' house.  I had two errands to run and then we started to drive home.  It was a particularly hot day today, so I thought we would go to the pool (my husband was going to be sleeping for a few more hours anyway).  I began to tell the boys what the plan was, but Bob had a different idea.  He wanted to play his PS3 when he got home, but SJ still wanted to go to the pool.  The temperature was reading at over 90^o, so I was started to try to convince Bob that we should go to the pool.  He wouldn't listen and was pleading to stay at home.  Meanwhile, SJ had run to get his bathing suit on as soon as we got home.  This is where my choice became difficult.  I knew if I sided with SJ then Bob would feel once again slighted by me.  He had just told me yesterday that "the little Mister always gets his way".  If I sided with Bob, I knew that SJ would have a huge tantrum and possibly disturb my resting husband.  What to do?  I decided to side with Bob.  He is right and I do sometimes choose the path where I know the tantrum won't occur.  I told SJ that Bob was not feeling well and he could just use the sprinkler in the yard.  He started to get so mad.  His face got red and he balled up his hands into fists.  He started to huff and puff.  I whispered in his ear (we were right outside the master bedroom) that if he had a tantrum I would take a few plushies.  He ran downstairs and began to whimper (fortunately for him, a very soft whimper).  I noticed that my neighbor was in her pool.  She had told me that the boys were welcome anytime.  I wouldn't normally assume they can swim, but I could feel the tantrum building.  I asked her if SJ could swim with her kids for a little while.  She said sure and I went back to get him.  He was so thrilled.  Bob got what he wanted, SJ got to swim, my husband got to rest and I didn't have to take any plushies hostage.  Tantrum diverted!