Frank conversations about sexual infections and a person's sexual past is the key to a long relationship, says a new study.
The poll of more than 1,200 15 to 24-year-olds cited talking about sex lives as a signal that a relationship will last.
According to the government-funded Populus survey, young people also consider it as a better sign of a relationship getting serious than meeting parents.
However, 73 percent admitted that they did not talk about sexually transmitted diseases before having sex with a new partner and 30 percent said they felt uncomfortable asking a new partner to use a condom.
The research, which was conducted on behalf of the government'sSex: Worth Talking About campaign, provides a snapshot of the milestones that this generation think important for a lasting relationship.
"These findings reveal much about the modern relationship game,” the BBC quoted Dr Catherine Hood, spokesperson for the Sex. Worth Talking About campaign as saying.
"While many young couples realise the significance of being able to talk openly about accepting tests for sexually transmitted infections, sheer embarrassment is preventing them from doing so, and potentially risking their sexual health as well as the future of their relationship," she added.