Ты see a huge паук on your Друзья shirt...you_____

I Любовь spiders, so I would tell my friend to stay still, catch the паук as gently as I could and let her go somewhere outside. There are no reason to kill spiders just because Ты don't like them.

Try to keep from laughing and see how long it takes them to notice, while glancing creepily at their рубашка every once in a while.
*evil laugh*

Scream and gtfo.

*shrugs* I'd take a jar или a cup and capture it and set it free far in the woods.

Point it out to them.

Scream and die *has fear of spiders*

Panic a bit and warn them.

If it's on the back of the shirt: Reach out discreetly and swipe it away at full speed.
If it's on the front: Just reach out and swipe it away at full speed, and knowing my closest Друзья I'd probably do so while screaming, "THIS! IS! SPIDERRRRR!!!"

I'd scream and say "OMFG THERE IS A паук ON YOUR SHIRT" then I'd grab the nearest blunt object and swipe it off their рубашка following up by either beating it to death или leaving it alone and running away. ( depending on my mood )

Say the word 'spider', so they knew why I was reaching for them. Get it off.
It would likely fall onto the bottom of my shoe and get squished (totally by accident) from there . . .

tell them.

slowly try to remove it from my friend shirt

Freak out because I motherfucking Любовь spiders