Gap created by the surgical removal of one's front four top and four bottom teeth (that is, teeth 7-10 and 23-26), facilitating the giving of non-toothy blowjobs to lesser-endowed men. Purportedly all the rage in North Dakota.
"Doc, you gotta help me out -- my man is demanding a love groove, professional ethics be damned."
In well physically defined bodies, its the pelvic bone. With pants still on(riding low of course), it almost looks as though a guide showing its way to the happy spot. Usually more apparent on men then females.
ex.1 A boy ain't nothing unless he has love grooves.
ex.2 Love grooves are love handles hot next door neighbor.