Bonding With Elves

I was thinking... Instead of sex often as the main factor that keeps the elves non elf partners from aging, it could be their presence and touch as well as the bond of sex that keeps their partner from aging. So if their apart for long their partner will start to age and if an elf lives with non elves as friends they too will live a little bit longer but not forever like a bonded elf and non elf pair would.

Have any ideas?

Have any ideas or suggestions? Just post here and ill respond ASAP!