Learning more about my gf [f] [21] secret’s [Part 1]

So i picked her up at 6 and we started our roadtrip to the camping space.
Some friend of us had picked a space near his favorite lake and we and 3 other couples were about to take a camping weekend there.

On our way there I asked her how the party was but she just said good and wasn‘t realy speaky.
I went on to ask her if she had fun and who she has been with there and also if they played some games.
She looked at me for a few seconds before she said: „yep played truth or dare with her friends but nothing to crazy happened under girls“. She now officially lied to me…
When we arrived the others were already setting up the camp. We greeted each other and helped them.
My gf and I had to gather wood for the campfire and as we walked past another camping space she ran towards a group of guys. None of them were at the party.
„So these guys are in my new class, i met them at a festival and then we went partying together a few times when sou were busy“
One of the guys put his arm on her should and the other guy next to her wraped his arm around her waist while kind of laying his hand right on her ass, gave her a few ass claps and then started to (she wore a short hotpant) slightly grabbing it.
My gf put his arm away rushed towards me and introduced me as her bf to which the guy reacted a bit confused.
„You gf is great, we have to go, see you guys a the big camp party“

Saw my GF [F] [21] being unfaithful at truth or dare and she does not yet know about me knowing it.

Well so this happend last weekend and I have not spoken to her since then. We both go to college and also got together last year in college. Our relationship is pretty vanilla.

She wanted to realy go to a pyjama house party of some popular dude who invited literally everyone we know. I told her that i cant because i had an appointment l.
I kissed her goodbye and let her go with her friends (all girls)

About 2h later i got there because i was finished earlier.
The party was outside on the garden where most people were and on the inside at the living room.
I searched for her inside as my friends told me she was playing party games with her friends.
As i went inside the kitchen i could see her (trough some kind of kitchen window next to the door) sitting on guys lap who was only wearing underwear. All of of her friends sat on some guys lap and they played truth or dare.
I watched from the kitchen which was way darker as they could not see me standing there and I wanted to check the situation before i pushed that guy away from my gf.