if I use facebook, twitter and g+ - the buttons are in 2

Hey,

if I use facebook, twitter and g+ - the buttons are in 2 lines. If i use 4 buttons, 3 are in 1 line. Where can in change this ?

You can see it here: http://seitensprung-sexkontakte.net/sextreffen-mit-tina/

Thanks for your help!