I have heard & actually witnessed this occurence. Since the amount of blended families are on the rise in today's society, I think this is happening more & more.
What do you guys think about "stepsiblings" in a relationship? When do you think it's appropriate? When do you think it's inapproriate?
I have my thoughts & views on this, but I would like to hear all of yours first...

If they are brought up living together as brother and sister, then I would definitely say "inappropriate".

However, if the parents are older adults, and the step-siblings are themselves adults, and have never lived together - then I suppose the waters get a little murkier.

Because having never been raised as siblings, these people are brought together more as friends, so I really don't see a moral problem with it - although it might make for some strange family reunion stories. <img src="/images/graemlins/crazy.gif" alt="" />

If - and only IF - there is absolutely no blood tie whatsoever, then there's nothing to stop it...they've been brought together by circumstance, not a common parent....

The only things offended are our social 'niceties'... In other cultures, for example,there is still a great deal of inter-family coupling, and this is considered the norm... We cannot impose a 'right' or 'wrong' judgement on that, but by virtue of the fact (as you rightly point out) the instance of blended and combined families is on the increase, maybe we need to re-evaluate what is socially acceptable and what is not....what makes us blanch today, will be absolutely run-of-the-mill tomorrow... Like inter-racial marriages, or women getting the vote...Unthinkable a century ago.....

I grew up in a family related by marriage.

My father's sister was married to the younger brother of my maternal great aunt's husband.

What this meant growing up is on holidays both my mother's and father's side of the family were always together, and today I have close ties with my many cousins on both sides.

God put rules in place for a number of reasons. First for genetics, Second for Health, Third for happy stress free life, and lastly to keep harmony in the family.

His law that you should not have sexual relations with a CLOSE relatives keeps the genetics strong and the family together. No one's trust is betrayed and there is still respect for ones parents and other family members.

That was a long time before blended families so does it apply to today. Yes, genetics are still the same. Blending families is hard enough without the kids engaging in sex. It shouldn't be OK for one to abuse the other or to take advantage of the other if one is older.

There are exceptions though. If the parents marry when both their kids are mature adults living on there own there are no genetic issues. There are no keeping the family harmony issues because they do not live under the same roof. As long as they are going to commit to each other keeping one another happy and healthy and it never effects the parent's marriage, the spirit of his law stays intact.

For the most part, it is a good idea for step siblings to NOT get sexually involved. The issues it would bring up in the long run could effect other members of the family and cause to much stress and problems within the family dynamic. The siblings relationship could bring stress to there parents relationship to the point that both marriages could be in danger of dissolving.

God's plan was for marriage to be a union of mutual caring, love and respect. Being human and selfish humanity has abused marriage and thrown it away. Keeping a family together is hard enough and the responsibility of all members.

If they were raised together since childhood as siblings, it's highly unlikely that a relationship like that would happen. But like I said before, not every stepfamily situation is like the Brady Bunch, so it should be looked at on a situational basis.
Regardless of past circumstances, if they are adults & can either move out of the parents house & get their own place either separately or together, then it really shouldn't be an issue at all. It's so difficult to find that special someone these days, that I don't think it's anybody else's business or right to interfere in the relationship especially if & when they have emancipated themselves from underneath their parent's roof.
I've seen my friend go through this with his girlfriend. They met through the fact that her mom married his dad. She was 20 & he 25 at the time.
Certain family members & even some friends gave them a hard time which eventually caused them to split almost a year ago. They perceived it as the same as an actual blood-related incestuous relationship, which imposed false feelings of shame, guilt & insecurities.
Now he's become miserable, less outgoing, & compares every girl he tries to date to her. She's now dating & acting out with a lot other guys who it's clear that the connections aren't as geniune as they were with him.
When 2 people repress their true feelings because of other people's insecurities & then because of that repression they begin to act self-destructive...well then it becomes obvious that those 2 people were good for each other & were meant to be together.
I'm more of a spiritual person than religious, but God may have brought their parents together for more than one reason. They are NOT blood-related & are consenting adults...we should live & let live & love.

I would agree that if there is no blood, and that they didn't grow up their entire lives together, then it is ok.

Sounds like they need a friend that will step in and support their decision to get together. Are their parents against it?

His Dad isn't against it, but the girl's mom is acting weird about it mostly because her parents, brothers & sisters are giving her a hard time about it. The mother's sisters & grandparents are causing all kinds of drama. They seem to be acting overdramatically, thinking & referring to the whole relationship as sick & incestuous. It doesn't make any sense because it clearly is not.
She just moved out & found an apartment so I think there's a chance they may get back together. I don't know, my friend has had a tough time with this & I seem to be one of few people that he's been able to talk to about it.
A lot of people seem to just automatically categorize this relationship as something sick & incestuous, which I am completely amazed by that ignorance. I don't get it.
No one seems to think it's a problem when the situation arises where the parents meet & start dating through their kids because their kid are dating. I hear that happens more often than one would think. There's really no difference.

I don't know all the details or reasons that the extended family is having issues. I don't know all the details regarding your friends or his father's relationship. As the institution of marriage disinigrates and more and more families blend seperate and blend elsewhere, there will be more and more questions like yours. Can the question of where the line be drawn ever be clear?

In alot of ways when mature adults, choose a relationship it shouldn't matter what others think. However, when advice comes from a loving heart, it is important to consider it.

What is not socially acceptable today may be acceptable tomorrow. Consider mixed marriages, sixty years ago it was rare, today it's common.

Your friend needs to sit down with the parents and have an open discussion on how each of them feels about it. Both of them need to respect the parents concerns.