They are at least, cousins, perhaps brother and sister with the information you give. This would make it problematical and illegal in many countries if it went further than dating
No. Because he is your cousin and its wrong to date family
No if the uncles "not related by blood" has a niece and the niece wants to date the uncles sister's son, it is not incest. Your not related by blood so every thing is ok. If some one is telling you that it is wrong show them scientific fact that you can find on google, just make sure it is a .edu or .gov some .org 's are also okay.
No, and it is illegal.
It is not okay to date your half niece. You are still in some way blood related and if you ever were to have a child together, it may be subject to deformities.
No you Incest lovers.
Any one can date you, if you love them and you'll become wife and husbands. Any body can date you except for things.
Why would it be illegal? There is no family relationship.
Yes. This is very possible. Especially if your husbands picture is anywhere else on the internet.
no its not wrong just let date whoever he wants to date
You can marry whomever you want. Morals are a different story.
To the best of my knowledge, it's not... technically... illegal to date your nephew anywhere.However, most locations do prohibit marriage and/or sexual relations between two people related that closely (at least if it's a blood relation rather than one by marriage, and sometimes in either case).
No it is not.