Friend help?

Okay, so lately I've been having a lot of trouble with my friends. Apparently, they don't think anything is funny unless it involves really inappropriate things. they joke about... Well, I'm not even going to say it here. But, they do joke about things thatbshould never be taken lightly, like suicide. :c
It really annoys me, since I hate that kinda stuff. I tell them to stop and that it's not funny, but apparently I'm the only one who thinks that it's not funny. I've been friends with them since kindergarten. They started this crap in like, Third grade, and I'm getting sick of it.

I'm wondering if any of you awesome people can help me get through this. Anything I can say to them?

Thanks in advance, guise!

I would kick them in the shins.
Or you can keep annoying them til they stop. Like, start poking them or say random stuff like grapejuice or lollipop.

Well,I know this may be hard,since you've been friends with them so long. But you should probably say goodbye. If you think they're not being appropiate(which by your example I would totally agree),then say goodbye. You want to know why? Cause eventually if you herewhat they're saying enough times,you'll start to believe it. And I would also suggest telling them it bothers you if you haven't already. If they laugh at ya,I would say DEFINITELY leave them.

Thanks, guys. <3 My one friend understands, but she's just... Really annoying in general. So I guess I can talk to her about it and get her more on my side.

Ugh, I remember those times.
People your age are always going to go through this stage, whether you like it or not. But that doesn't mean you have to put up with it, and its good that you're not going to tolerate it any longer. Tell them you don't like it and that it makes you uncomfortable, and if you're ridiculed/cast aside for whatever reason, then they aren't truly your friends that really care about you.
Don't stay idle. If you don't like what's going on, then voice your opinion.
... But, by the same token, don't expect them to all understand. Not everyone will accept that you don't share their really perverted/perverse sense of humor, which is the sad truth.

Protip: Perverse is a totally different word meaning from perverted. Just clarifying that Zellie isn't an idiot.

(Oh, guys, when I said they've been doing this since 3rd grade, it's not like that was a year ago. xD I'm a lot older than 4-5th grade. )

Thanks, Zellie. I'm not sure they'd listen, but if not, and if it comes to this, I can let my parents know.... But I kinda wanna try some other solutions before I have to do that.
Thanks for your help!