None that can be trusted as sure. Men (and women too) are simply too complex to have such a simplistic definition system. The only way you will find out if he's bisexual, gay or straight is to ask...
Well you'll have to make an account . to make an account you'll have to click on new user and then you'll have to put in the user name you want and your password and when you put in you password you...
There may not be any specific signs, some people are more open to these things than others are. Additional answer: there is no reason to be "alerted" to a woman's bisexual orientation than to be...