I have a dear friend whose son is the same age (same birthday!) as my son (both 2.5). We get together regularly (1-2 times a week) with the boys and they really enjoy each other. Unfortunately, her son is a bit aggressive. He often hits, throws sand at, or kicks my guy. Although my son isn't an exclusive target, he does seem to be more aggressive toward him than other kids (but my DS is tiny and he is on the bigger side, which probably plays into it).

When something happens, my friend always addresses it, tries time out, makes him apologize, and if the behavior continues, takes him home. I feel like she's doing her best, and she feels awful when her son behaves this way. We both try to prevent the behavior, but it often comes literally out of nowhere (not retaliatory, etc). They can just be playing one second, and he pushes the next. She always encourages her son to give my son space, but that doesn't always prevent it (she also has a 6 month old, so she can't always be as close to him as she'd like.

My son still likes her son. He will say "friends name no hurt me" when we are starting to play, but if I ask if he wants to play with him, he always says yes. He says he is nice and understands that he is making a bad choice. When something happens, I always encourage DS to talk to me and later his friend about his feelings and point out that friend is in time out because of his choices. My poor friend is at the end of her rope with the behavior and feels awful (when it happened today she sobbed and repeatedly apologized and asked why we are even willing to play with them.) So:

1) would you continue to arrange play dates? If so, any tips on helping them play safely?
2) any suggestions for my friend (she is more than willing to hear advice, especially about this issue)
3) any suggestions for me as I talk to DS about his friend's behavior? I encourage him to verbalize "stop" or "I don't like that" but he generally won't.