Don't feel guilty. My own sons were playing indoors this afternoon with the neighbor's little girl. Temperature feels like 110 where I live, so it was too warm to keep the playdate outside.

What is your alternative? Keep your child isolated for the next 2 years?

OP, if you're going to feel guilt, you have a bigger problem than exposure

We just moved and our kids have been playing with other neighbor kids outside for the past few weeks. They're the happiest they've been in MONTHS. They ride scooters and bikes and play hide and seek but I don't think any of them have actually touched or come into physical contact with another kid so I guess we're "safe".

We also let our older son go to golf camp!

Same. I am dreading the winter. Unless the situation improves, I won’t feel comfortable with the kids playing inside.

Outside is fine. If you are really worried, have him wear a mask and make sure he knows to stay 6 feet apart. Otherwise, let the kids play outside.

Well my kids are at camp playing with other children so...

Ok. We have also been strict but let our kids play outside with others. Are you looking for people to say things like that or do you want people to flay you so you can make yourself suffer because you feel bad? Honestly, let it go. You're going to make yourself crazy.

I think it’s fine. Outside with older kids is very low risk. Just make sure he washes hands.

Its fine OP.
My 7yo was doing the same thing with 2 neighbors until it got too flippin hot.

“Caved”???? This is allowed under the state guidelines. Everyone I know is allowing outdoor play dates.

We’re doing something similar with the family across the street. Community spread is low where we are. We’ve all reduced our exposure generally. I’m okay with expanding our bubble to their family. It’s a risk, yes, but it’s just the kids playing (us parents hang out in our respective driveways across the street from one another) and they only play outside. It’s a trade-off I’m willing to take for now.

Is there a question here?

We completely isolated ourselves starting in March. DH and I are both working from home and are busier than ever. Our only child, a very social six-year-old boy, has been miserable with Zoom classes and virtual playdates. Until March, he really was thriving, but his behavior and attitude has really suffered since then. About 10 days ago, we caved and started allowing him to play outside each afternoon with two of his friends on the block. He is so happy and looks forward to the playdates all day. I feel guilty about exposing him (and us) to a potential risk, but I felt guiltier about keeping him isolated and away from any peers. I really do worry about the damage that could do over the long run. I assume that we'll be back to total lockdown by mid-fall, so I want him to socialize while he can.