Is it weird to WhatsApp guy I met in park

[Saturdaymorningsinthenineties]

Last week during school holidays I took my young Dd to a local park with playground, it’s a quiet one where many don’t go. Another little girl was there and Dd began playing with her, her dad then came up and was really friendly and great to talk to.
I live in another country and he spoke great English, although from a different country to the country we both live in now. Our DD’s are the same age and we had a good discussion about schools/life where we are and agreed on many of the issues about schooling etc. He was really interesting and easy to talk to (as have other mums I’ve met at playgrounds etc been to) and the girls got on great. As we were leaving I said maybe we should swap numbers, mainly concerning possible future plans he may have to homeschool with some other parents he’s met, it’s unlikely to happen for my Dd, but is an option depending on how her first year in primary goes in September. He was very open to it and said they would be there every morning that week. We didn’t end up being able to go again and it’s back to school next week.
Should I WhatsApp him? But say what? I feel a bit rude to have not messaged, but also it seems a bit strange? I also never ask for peoples number and don’t understand why I did really

My DH swapped numbers with a woman he met in the park as our kids were getting on well. We'd just moved to the area and didn't know many people. We now meet up regularly with the other family and have become good friends, and the kids adore each other 🙂

Everyone is a stranger the first time we meet them, that's how people make friends 🙃

You've completely missed the point 😑

I haven't missed any point, everyone is jumping on OP and she's almost convinced herself she must have a crush subconsciously that even she doesn't know about! Pp's are pretty much hysterical about a normal interaction that wouldn't be given a second thought usually but because they're opposite sex everyone is twisting it. I'll repeat. The reason she is second guessing it/ what pp's perceive as obsessing over it is because of people like yours reactions expecting it to be anything other than friendship and a playdate with the kids.

Sorry, misread the post.

She was clearly second guessing it all before she even posted on here, or she wouldn't have posted in the first place.

She's also the only one who's said he made her feel weird and that she's been thinking about him and their interaction all week.

I've personally never had a platonic male friend that's made me feel weird and that I've thought about all week since meeting them - that's how I behave when I have a crush.

I think OP has the beginnings of a crush and needs to stop right now before it gets difficult. People can have platonic friends, sure, but they don't usually fret about texting them or overthink every interaction with them.