I have a problem with calling any of those guys straight. They would have to be bisexual, right? It seems to me that a lot of people think that bisexual means actively seeking both sexes romantically, but I define bisexuality as "the willingness to engage in consensual sex with either sex." I have a "straight" friend like that, that insists that he watches big-dicked porn stars "because he respects a monster D" and I don't question him, but in the moment I always think "No, you get turned on by huge D's."
To answer your question, when you get the chance, you should tell them that there is nothing wrong with:
1) seeking a man for sexual pleasure
2)not being straight/being bisexual or gay like your one friend said
and, if youre feeling bold
3)that you're more than willing to help them when they are sober if thats what they really want.
Sorry to rant, but lately I've been really offput by the insistence that guys can be actively seeking to fuck and even get fucked by guys and still be called straight. Because they are literally not. Like, we all know how attraction works. Most of us could not be paid to do anything sexual with a woman, and yet when it comes to masculine guys, the majority of guys bend over backwards to defend the "straight" label. I think it stems from internalized homophobia+biphobia, and porn's insistence on making "seduce the straight guys" type videos. And, personally, most of the bisexual men that I know, live a double life. Their gay friends know they are bi but their straight friends dont... like, that's how far some guys go to hang on to the "straight" label.
Being gay is ok, and I think we need to do more work in saying that being Bi is ok.
