Quote from cronosilver
what would you do if you and you boyfriend/girlfriend just started going out only to find out later that your parent and their parent had been dating for a while and were going to get married?
Sounds like a movie that I would probably watch lol. But, on to your question, I wouldn't find it a problem, your not blood related or anything. But it would be awkward if you all lived in the same house. :/
But if it makes you happy to win on the internet, have at it.
Living La Dolce Vita, Life couldn't get much sweeter <3