Evolutionary speaking,what is the purpose of 'teat' for men?

OK folks we know that the main purpose of teat in women is an asset for feeding our newborn baby. Men have teat too,but it seems like they have no (evolutionary speaking!,please) real purpose for reproduction or to sustain themselves.

Our cousin,other primate family member too have the same main anatomy as we do,teat is also present on males,but they never use it for reproduction means. There’s no licking or such sexual stimulation for their teat but it still exists there,and this is an unique trait that only presents in Primate family.

So why Primate family,including men,still posses teat till nowadays? Is this just a trace that left behind by our evolutionary process? (like the ‘pseudo-feet’ in anaconda family).