Considering how much they'd been drinking, I'm not surprised they had the idea to have a threesome. Especially since the mom is such a badass. Kissing your daughter in front of her boyfriend meant offering yourself up as a pussy for copulation. And the guy took advantage of that offer by banging both of them. He even shared his sperm with his mother when he came between his girlfriend's legs. Damn, that's fair!
I must say the lady is very experienced - her front is developed to the limit! Too bad she sucks so little - she clearly does it professionally! When the cock falls into such an experienced mouth you want the lady to suck it to the peak and swallow the cum. And then, when your pleasure was just off the scale, she continued to suck his cock slowly and tightly! And then, after a little break, it's nice to put the lady in the cunt and slowly fuck her for a long time!