What to do if I see someone I know at the gym?

This might sound like a stupid question, but today I went to the gym way later than I normally do (I normally get there at 6AM, today I went at 11AM) and I saw someone who is in one of my small classes (of about 6 people). I didn't actually look at them because I never look at people in the gym and secondly because I look like a mess because I don't shower before going to the gym (who the frick does that?) so my hair is kinda bed-hairy, which makes me look like a hobo.
Basically, I kinda just spent my rest and recovery on my phone looking at mushrooms while he and his friend worked out. I felt too awkward to say hi because I looked like ****, he was with his friend and don't talk much in lessons. I feel kinda bad if I think about it because he might have taken it badly (that I blanked him and that I hate him for no reason). Should I message him on snapchat asking if he went to the gym or is that too weird or should I just forget about it and assume that they didn't recognise me, hence why they didn't say hi or anything, or should I accidentally bump into him again at the gym and act all surprised like "oh i didn't expect you to be here, did you happen to be here last tuesday? oh I wasn't 100% sure it was you hahahah"
Thanks for the advice on this very crucial matter thx

Damn, I though I overthink things...

It's not overthinking, it's intense analysing.

Why was you looking at mushrooms?

Tbh I do the same thing when I see someone I know anywhere I'm not expecting them. I do it not because I don't like them, just because I don't want to experience that cringey small talk

"oh look it's you fancy seeing you here"
"oh yeah just out doing a bit of shopping, lovely weather today"
"yeah it is lovely isn't it"
...
...
...
...
"well best be off now"

Why was you looking at mushrooms?