Is there something wrong becoming romantically involved with a third cousin...?

Question:Not usually. If hemophilia or half a dozen other genetic diseases runs in your family, yes. Otherwise, no.

Look at http://www.tedpack.org/cuzdate.html
for more than I want to paste here.

Anyone whose ancestors were in the USA, west of the Atlantic seaboard before 1880 or so has cousin marriages in their lines. I do.

There is one caveat - if your families are close enough you celebrate holidays together, then there will be some awkward pauses if, for instance, he takes you out for what he said was dinner and a movie but tries to set the county speed record for getting your bra off. Likewise if he asks you out and you decide what the heck, he's family, so you don't bother to bathe and you chew with your mouth open.

That is, if either of you break it off because of a flaw in the other, you will still see each other, so it will be awkward. You should both be on your best behavior while courting.

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Added afterwards:

Dart Swinger is wrong. Third cousins are children of second cousins.

First cousins have common grandparents.
2nd = common G Grandparents.
3rd = common GG GPs.

3 times removed would be a cousin of your great grandparents; their 1st is your 1C3R, their second cousins are your 2C3R and so on.

Best Answer - Chosen by Asker: Not usually. If hemophilia or half a dozen other genetic diseases runs in your family, yes. Otherwise, no.

Look at http://www.tedpack.org/cuzdate.html
for more than I want to paste here.

Anyone whose ancestors were in the USA, west of the Atlantic seaboard before 1880 or so has cousin marriages in their lines. I do.

There is one caveat - if your families are close enough you celebrate holidays together, then there will be some awkward pauses if, for instance, he takes you out for what he said was dinner and a movie but tries to set the county speed record for getting your bra off. Likewise if he asks you out and you decide what the heck, he's family, so you don't bother to bathe and you chew with your mouth open.

That is, if either of you break it off because of a flaw in the other, you will still see each other, so it will be awkward. You should both be on your best behavior while courting.

======================================...
Added afterwards:

Dart Swinger is wrong. Third cousins are children of second cousins.

First cousins have common grandparents.
2nd = common G Grandparents.
3rd = common GG GPs.

3 times removed would be a cousin of your great grandparents; their 1st is your 1C3R, their second cousins are your 2C3R and so on.

People married first cousins through almost all of human history and still do all over the world, 3rd cousins is fine.

Even the offspring of 1st cousins only increases the probability of genetic anomalies by 1-2%.

Yes, on many levels. A third cousin is the parent of your parent's first cousin. Maybe you meant your first cousin three times removed. That would be worng, too.

Legally - no problem.

Genetically - minimal if any problem.

If there is a history of a genetic disorder in your family associated with the lines coming from your common 2nd great grandparents that would indicate the abnormality was dominant. But being dominant, if neither of you have this abnormality, then you are "safe". There may be a recessive abnormality. But because of the distance of your common ancestor, each of you would only have a 6.25% chance of having this recessive gene and any child would thus have a 1.5% chance of inheriting the condition. (would only get it if both of you passed the recessive gene). Pretty slim. Of course if one (bad) or both (worse) have this disorder, well, you really might want to consider other options.

The biggest issue is probably cultural/family issues. Is this acceptable in your family - BOTH of the families? Yes, you can always fall back on the "I'm my own person, I'm doing what I think is right, if you love me, deal with it" argument. But is the potential relationship really worth the heartache (if any) it may cause in the family.

That's a personal/family issue nobody can answer but you and your cousin as you know your families. Just something to consider.

lt is considered legal. Nothing wrong whatsoever except the too conservative ones who can't accept it.

Most people do not even know there third cousins, so yes you are fine to go ahead, be happy.

Yeah it is gross.

Family is family no matter how far back you go. My Grandparents were first cousins and married. I just found that out by doing a little genealogy on my fathers' side of the family. I think it is GROSS!