There is no conflict, and happy things are not afraid of conflict.
Even if you get married, you have to go to the ancestral graves to worship, which is called visiting the happy graves. But every place has its own local customs. Specific situations will be treated on a case-by-case basis. There is no such particularity in Feng Shui.
Generally speaking, it depends on customs and habits. In some places, Spring Festival couplets cannot be posted three years after the death of an elder during the Spring Festival. To show respect for the elders in the immortal world, but if the children in the family get married during the past three years and are so happy, then it is no longer taboo to post red couplets during the Spring Festival. Because something festive happened in the middle of the way. Then the newlyweds also go to the cemetery to worship their ancestors.
In short, customs are the main thing.