To bisexuals, how is it you are attracted to both when?

they are so different? I can find beauty in a man or woman but when it comes to sexually I am trying to understand how two polar opposites could be equally pleasing. Men tend to be hairy, rougher skin, rougher touch etc. Women tend to be smooth, sensual etc. There are more differences I know but I think you get the drift. Also, is there one you tend to gravitate to more often and feel you would be happier with in a long term relationship? This is not meant to be offensive, but the only way to begin to understand something is to ask questions. Thanks.