A most baffling headline: Security 'bad news for sex drive'

And the lede of the article is even more baffling:

A woman's sex drive begins to plummet once she is in a secure relationship, according to research.

What the heck is "secure relationship"? Does it have something to do with all kinds of security outfits? The War on Terror? DHS? Shin Bet?

And what should a man do to avoid it?

Consider me deeply confused...