Yes if I remember correctly, they get shorter each time, and when that buffer is used up, you won't last long as replicating cells will have to work with incomplete blueprints.
An interesting recent discovery is that boys get the length of their telomeres not just from their dads, but from the age of their dads - the older your father was when you were conceived, the longer the telomeres. In that respect my son is better off than I am, as I was ten years older than my dad when he was 'created'. (Though a famous writer here conceived a son when he was 65 ... - telomeres are likely not going to be his problem!)
Could it be that men who are fertile longer just have longer telomeres or something? In other words maybe it is not cause and effect, but both just in response to having good genes or something.