Family/generational epic drama full of secret

I read it in french, not sure if it was a translation. read in the early 2000s(2004-2009). a rich family's daughter(rose? falls in love with a poor family's son. they have sex(in a lake? both inexperienced). the poor smart son and his brother moves away soon after to find a better life. unbeknownst to him, she got pregnant. in the new city the smart gets liquored up and taken advantage of and that new girl also get pregnant unbeknownst to him. his brother marries that girl and raises the kid as his own. the two kids meet up and fall in love and the whole family finds out all the secret. the two kids are devastated by the news and kill themselves by drowning in a lake.