What if you had cousins who are basically like sisters to you doing stuff you don't approve off and you wouldn't do in a million years? e.g sneaking around with guys behind their parents backs

I'd state my opinion and stop hanging around with them. After all, it is their call.

oh sneaking with guys? are they having rampant sex or are they just talking, maybe kissing the guys?

i thought they were doing drugs or something lol.

i know it's a very bad thing round your way, but i think it's a very natural thing in adolescence. if it's bad, please don't go sneak on them with their parents, but do have a good talk. and don't abandon them. if they are like sisters, your love should be unconditional whatever they do.
you don't like what they do, not them as a person.

Sit with them...ask them why they are wanting this kind of attention...see if there are other activities out there that will hold their attention...somthing they have a passion for........that will motivate their hearts to get out there and do something worthwhile and maybe all that extra energy will go into a positive outlet.

I ignore and enjoy their company. After all, they are my cousins and as long as they are not harming me, why would I stop hanging out with them?

If they ask for my advice or opinion, I'd give it to them honestly.

I'd give them my point of view and advise them, i wouldn't stop hanging out with them though.
actually it also depends; sneaking around with guys, doing what?
Sometimes trying to help can end up very badly.

Report to their parents, because if some thing bad happent to them then you are blamed.

I am with EVilfire but before reporting i would advice and talk to them.

I will tell them honestly that I know what they do behind their parent's back.
But I won't stop hanging around with them .. I have my mind & I know what's wrong and what's right for myself.
I'd talk to them & tell them its wrong, if they wanted guidence.
Other than that, I can't just tell them to stop doing it, coz I know .. They won't stop. :)

Advice them, if they continue doing what they do, I'd stay away from them or not be as close to them as I was. However, I wouldn't want to be associated with them. I've experienced something similar to this recently and realized that the best thing to do is to make it clear to them that you don't approve with what they do, and any remaining relationship between you and them will still be there just because of the history between you guys and the memories you shared together. At least that's what happened in my case.

I won't tell their parents unless they're pretty young and immature. However, if they're adults, then I would advise them over and over again. If it doesn't help, then I ignore their bad habits but I would not stop hanging out with them especially if they're my good friends and cousins.

We do not have real relation with my cousins. I am glad :p

Advice them, if they continue doing what they do, I'd stay away from them. I don't want to be associated with them.

same here, or at least not be as close as i once was. i noticed that i usually feel uncomfortable if i hang out with someone i don't approve of his/her actions. i'd still like them, but i don't know..i feel like there is something heavy on my chest everytime i remember.

this happened to me about 4 years ago..n it ws about guys.. n my cousin was very young at that time n was influenced by a bad gang of gals.... so kinda hinted it n she totally denied.. i collected proof.. numberrs n chat logs.. i then confronted her.. she couldn't lie then ( i felt like i was the FBI ) but i was so afraid she was gonna hurt herself or some guy would trick her to do something.. she was 14 at that time..

she then admitted n told me everything n i talked to her n told her y i think its not right n about the age n what would happen.. n she digested it very well.. n she stopped doing it.. n only stuck with 1 who she claimed she loved n loved her back.. we're still close now.. n now she's engaged to him n im so happy 4 her :D

I would advise them to use proper protection & screen the guy for STD's