Play dates not working out!

So, my boys are going to be 7 this month and we have tried all sorts of play dates, but they never seem to work out. One or the other ends up crying because they feel "left out." They play with both boys and girls, so I've tried 2 boys, 2 girls, a boy and a girl and nothing is working. How do you do play dates so everyone has a good time? I was thinking of inviting 1 friend over and have the other boy go to someone else's house at the same time, but I'm not close enough friends with any of their school friend's moms to call and ask if they can come over.

For now I think they can just play with each other!

ETA: I have a twin mom friend who's girls are 15 and she said her girls never had this problem. Is it a boy thing?

 

Today the boys had an early dismissal. Marcus had his "BFF" over, and Jonathan went across the street to play there. I have found it always is better if they are different places. Although Jon will do better if Marcus has a playdate, if it allows Jon uniterrupted time on the Wii.

 

My boys are 5 and generally do well with play dates. There is another set of twins that we do play dates with somewhat frequently, and the 4 boys get along great together! There are times when 1 wants to do something different than the rest, and one of the other twins can be moody so that usually is the problem. However they were over today for about 3.5 hours and they played great the entire time (not 1 issue, I was a little amazed). I know that the other set of twins does have issues when they have play dates with some particular other kids (that is another reason why the mom likes to get together since the boys do so well & even include the other boys little brother).
Sometime we have another friend over, and the 3 get along great too. This friend is really easy to get along with, so this is not surprising. My boys are pretty easy to get along with and 1 will go along with whatever most of the time, which helps.
The kids play lots of different things. Today playing hockey in the hallway was a big winner, as was playing in the backyard.

 

My boys are the same age, and generally, we only have 1 friend for both of them to play with. I think they do great that way, and we have rarely had a problem. I think it has a lot to do with WHO you are inviting over. There are a couple of the boys' friends that are NOT allowed to come for a play date, way too rowdy... And surprisingly, my boys are good with that.

 

We have also had problems with play dates (boys are 7), though it is usually that the more charismatic older brother (9) ends up stealing the show, the twins are both pretty shy and have the added pressure of not being so confident in the language (we're native English speakers living in Croatia). Their older brother is far more self-assured and fluent in the language.
The twins are better at sharing their friends if they get to decide whether the other twin is involved or not, so that sometimes they get to play alone with their friend, then the person stays *their* friend and doesn't get "stolen" out from under their nose. We've also put the other one on the computer during a play date.
Separating them during a play date seems worth a try, could the other twin have a play date with you maybe? If they knew they weren't supposed to be included because they had something else cool to do it wouldn't feel like being left out.

 

It has gotten better, but did used to have a lot of problems with 1 of the kids being left out. It think it might be the age. Now, at 9, it is much better.