Is it ok to masturbate with your sister?

I think its a bit of both but hey if you enjoy it then its up to you what you do.
At least you can get tips off your sister :-)

It is certainly not weird, in fact I agree with "her friends" and think that it is pretty hot. You can compare notes on what works for you both and it should reinforce the bond between you.

I think it would only be weird if you were like touching each other because me and my sis do the same thing but we only masterbate

Yea me and my sister do it to buy we help each other sometimes

I and my sis masturbate in front of one another . It is fun and she and I have found that this active has made us both closer.

I always wanted to jack off with my sister but it never happened. What a downer! Now I’m 63 and she is 60

It's more fun if you do touch each other. I meanlike, so long as you are both girls. My big sister showed me how to masturbate. But I couldn't orgasm at first just doing it myself, so she did it to me. Now I can do it as good as she can.

ps We still masturbate each other sometimes.

How do you start something like this with the opposite gender sibling?

no need to worry about it, if both u and ur sister are ok with it, then it's fine

As humans, we don't come equipped with a "user's manual" to help us sort our how we work, sexually and otherwise. So, we have to experiment, or be taught, or both. And the people we most often turn to to help us in this way  are those closest to us as we grow into these new feelings and desires -- our friends, siblings and cousins. It would seem (and I suspect that it IS) natural for siblings to begin to explore masturbation together. This could continue for a long period of time, or the shared interest could wane, or one of the siblings could leave the home and lose contact with the other. In any event, it is likely very common for siblings to connect in this way, and is certainly better than fumbling along on our own!  

I think he means how do your start it like begin to do it.

How to begin such an involvement with a sibling or cousin? There doesn't seem to be a single, "one size fits all" answer to that. Every situation is different and would respond to different conditions. Leaving the societal strictures against incest of any kind aside for the moment, here are some general thoughts:

Sexual involvement with a sibling (or cousin, friend, roommate, what have you) -- of any kind -- must be mutually arrived at. That is, both of your heads must be in the same place at the same time. That is the most difficult thing to assess. However, most siblings, if they are close enough in age, will likely approach the wonders of puberty and sexual maturity at roughly the same time. Interest in things sexual will begin to develop in both siblings closely enough that one observing the other's masturbation for instance, will become a "secretly shared, special experience" rather than something to be reported to Mom or Dad. One sib can lead the other through the mysteries of puberty in the same way they might lead the way in other life experiences such as learning to ride a bicycle or diving into the pool without fear.

Generally, close proximity while growing up together is fertile ground for one sibling to observe the other becoming more frequently sexually aroused, perhaps accidentally catching them exploring genital sensations or masturbating, or  engaging in conversation about new awareness of things of a sexual nature.The younger sib might easily become aware of the sexual activities of the older with a boyfriend or girlfriend in their room, or they may ask questions out of simple curiosity -- if the sibling relationship is adjudged to be appropriately safe, intimate and trusting.

"Accidentally" arranging for the (usually) younger sibling to see or hear the other engaging in sexual activity is one way to test whether this relationship can advance to a shared sexual level. Sometimes it can be an overt request by one to see the other's genitals or to explore newly discovered (or heard about) masturbation techniques, or even "see how babies are made", etc. This requires a delicate assessment of risk, and a trust in the other not to violently reject the idea outright. REGARDLESS of approach, the issue should never be forced. Sexual contact with a sibling, cousin or friend MUST be consensual, gently eased into, and mutually desired and pleasurable. It's a delicate dance with someone whom you trust, and who must also trust you.

You are describing Grooming