It is in VR.
Don't forget that the Internet is cybernetic, it plugs into your head like the Matrix
There's surgically implanted nanomachines at the temples.
So VR sex is indistinguishable, it's better than real because people can play characters, like an interactive game
Only those who are truly madly in love and want to have babies bother with real sex and marriage.
Or Space colonists, who are driven to pump out kids for the colonies
Single people date in VR, so the sex is totally safe with regards to hygiene.