hetero lifemate 

A best friend who is so close, that were they not to match your sexual orientation, you would be married to them. Other sexual orientations may use "homo lifemate" or equivalent.

Yeah Dave's my hetero lifemate. We tell each other everything.

hetero lifemate by Dustin Freeman November 30, 2005

hetero-lifemate 

your closest friend of the same sex, the person you'd be with if you were both homosexual.

*on the phone*

jack: "i miss you man, when are you coming home?"

phil: "next thursday...only 5 more days!"

jack: "i can't wait to see ya bro, i have so much to tell you...you've really been missin' out!"

phil: "i love you, man!"

jack: "i love you too, bro!"

*off the phone*

tina: "man, if i didn't know any better, i'd think you two were gay together!"

jack: "shut up! he's just my best friend, my bro, leave me alone!"

tina: "don't get so deffensive...i know you two are just hetero-lifemates."

hetero-lifemate by girl7 December 8, 2006

Hetero Life Mates 

Two people of the same gender and heterosexual orientation who decide to be each others life partners, but asexually; living together but unromantically.

Diane and Mary decided that if they were unattatched by the age of 35, they would move to NY together and be hetero life mates.

Hetero Life Mates by anon December 18, 2004

Heterolifemate

A platonic soulmate. aka a friend you wouldn't fuck.

She's not my best friend. She's my heterolifemate

Heterolifemate by tarancegeezy January 16, 2011