12 yr old home alone

HI-

 I am looking for some advice/opinions on this issue. My ds is 12 and lately has not wanted to come with me if I have to run errands, take younger ds somewhere, etc... I don't mind if I am only gone an hr. or so but I do not feel comfortable leaving him long perionds of time like more than 2 hrs. He's a good kid but still, I personally think too long alone is not good.

  Now that it is summer vacation, he wants to hang with friends, play video games, etc... and does not want to do the things younger ds does or go visiting cousins ( he thinks it is boring) My 2 boys are 5 1/2 yrs apart. The 12 yr old is giving me a hard time whenever we make plans to go somewhere. Once in a while I asked one of his friends parents to check in on him but I will not do that too often, I don't feel it is right plus then ds thinks he will never have to go!

  How long if you do, leave your 12 yr old home alone? Just wondering. Thanks! It is going to be a long summer!!