The joke is that from the flip side maybe he just married her for her washer and dryer. I'm not saying it's a good joke, but I don't think it's bad enough to merit that many downvotes 🤷🏻♂️
This is my take as well. She wanted to go on the date with him and he later realized it. Not sure if there's meant to be a joke, to me this is a wholesome tweet.