There can be an early fruit or two on tomatoes, it isn't unusual. Your plant is hitting it's mature stride now. You have lots of flowers and those should develop into lots fo fruits.

I don't think you're quite there yet, but be aware that when high temps are above 90F, and low temps are above 70F, tomatoes won't set fruit. You'll have lots of flowers and no fruit. Down south, tomato cultivation is a race between the last winter freeze, and the summer heat. Sometimes you lose the race.

Beesneeds is correct and you'll get more tomatoes later but from I read not many for Mr. stripey. It's a common characteristic of big beefsteak varieties and seen it all the time growing many different beefsteak cultivars. The plants focus is producing seed and will devote a lot of nutrients and energy to that one tomato and then it takes off later in the season, and since I'm in Zone 4 I rarely get more than 6 to 8 tomatoes before frost. I've basically ditched beefsteak cultivars, and don't need a few 1 to 2 lb tomatoes on a plant taking up space, so I prefer and focus on 100's of 8 to 12 oz tomatoes over the season.

I grew Mr. stripey about 8-10 years ago for one season and didn't grow them again, so there must of been something I didn't like but I can't remember. Going through my seed packs I keep in the freezer I decided to give Mr. Stripey another try this year, because I always give every variety a second chance before trashing the seed pack and by golly they germinated, so I have one in the garden. I'm also giving Virginia Sweets and Chef's Choice a 2nd attempt to prove themselves after growing them last year to verify why I didn't like them, but honestly I couldn't tell them apart by appearance or flavor, but my mom loved them so another reason I'm growing them again. I do have a strange feeling Mr. stripey grows like them and may even taste and look like the other two, so I will see this year if they all get tossed.

I'm still trying to find the perfect indeterminate which rivals the flavor, yield and nearly bullet proof like my semi-determinate Celebrities. Better boy and Mountain Rouge are good contenders and both are AAS winners from past years. I grow Mountain Magic exclusively now for small 2 oz. tomatoes which are the first to produce and till the season ends. They're the most bullet proof plant I've ever seen in every category, and produces 500 to 1000 tomatoes on each plant without any cracking or other fruit issues. Yes I and two other people count and log tomatoes picked including the cracked ones. Record is 998 with only 5 cracked tomatoes. Ditched all the Cherry Tomatoes forever for Mountain Magic.

I thought the highest night time temp. for tomatoes to set fruit was 74F?

We're above that here where I live, at this point.

Not sure how far southeast you are in GA, but I looked at NOAA, and Brunswick temps are highs of upper 80s-90F and lows between 70-74F.

Different tomatoes have SLIGHTLY different levels of heat tolerance for pollination. Mr. Stripey is alleged to be one with more heat tolerance. But my experience is that the difference between tolerance and intolerance is just a few degrees, so it may make a difference of just a few weeks in how late pollination can occur. Almost certainly, if you have lots of flowers, and a big plant that can support lots of fruit, but pollination isn't happening, it's because of the heat. If you can keep it going until fall, it will start to pollinate, and you might have a chance to get ripe fruit before a freeze.

If you planted out in March, and it's five feet tall, it must be a very healthy plant, and I have to be a little surprised that even if you're not going to get any more tomatoes for a while, you haven't already gotten a few. Did you have many flowers a month or two ago when it was cooler?

The Mr. stripey seed pack is going into the trash. Not good for the second time around and would have a hard time giving them away the tomatoes. The free Terra Cotta seeds I received from a seed order is also getting trashed, another bad tomato cultivar they try had to give away.