This term is used to refer to the fact that once lesbians move in together, settle down and get older, they tend to never have sex with each other ever again, unlike gays, who just have sex with any asshole they can find. As anyone with a penis would know, it's difficult to get a woman into bed especially when married. But when there are two women involved with no cock pestering them there is noone in the relationship who gives a shit about sex anymore, therefore causing lesbian bed death.
