Girlfriends are not cheap. Research has shown the average relationship will set you back a whopping £1,426 a year. Much of which is made up of garish lingerie, thigh-inflating chocolates and other fluff-addled tat bought in a desperate attempt to encourage fellatio. So it’s only fair that you treat yourself once in a while. And if you can do that while making her feel like you’re the most thoughtful man in the world, even better. After all, what she doesn’t know about won’t hurt her. Except, eventually, Chlamydia.