I'm a gynaecologist, and have seen more vaginas then you'll ever get your mouth on. Believe what you want, but your vagina was designed by Mother Nature to take a penis, and lesbian sex is no substitute, as female induced orgasms via your clit won't ever make you pregnant. Peace.
It's just a staged performance you dafty bint, besides lesbian sex is only foreplay, and the fact they use dildos or a strap on shows they still need one of them to be a man.