What we called "soft porn" in the 80s (meaning - still acceptable to mainstream viewing in movies/songs) is gone. Most of this category is without past limitations. Sex is also openly shown, of course. Birthday Sex by Jeremih and Leavin’ by Jesse McCartney show explicit sexual content, McCartney’s with young teenagers.
Other explicit aspects of this category of songs are simply the words. Britney Spears got the attention she was looking for with “all of the boys and all of the girls are begging to If You Seek Amy” (you have to say it out loud). Drake’s song Best I Ever Had (*lyrics changed on youtube) simply defines explicit:
You the fuckin best, you the best I ever had...
My shirt ain’t got no stripes but I can make your pussy whistle like the Andy Griffith theme song
And who told you to put them jeans on, double cup love, you’re the one I lean on
Feeling for a fix, then you should really get your fiend on yah, just know my condo is the crack spot
Every single show she out there reppin’ like a mascot
Get it from the back and make ya fuckin’ bra strap pop all up in your slot till a nigga hit the jack pot
Then, to top it all off, we have My Humps, by the Back Eyed Peas, a truly shocking thing to hear your tween singing Fergie-style in the shower
You love my lovely lady lumps, my hump, my hump...
What you gon’ do with all that junk, all that junk inside that trunk? I’m gonna get get get you drunk, get you love drunk off my hump.
What you gon’ do with all that ass, all that ass inside them jeans? I’m a make make make you scream, make you scream, make you scream.