I'm not open with my mates about being bi, but my GF knows I have urges. She supports it because she has a DP thing. I don't let on to the guy candidates because I think it would put them off, instead I lure them by saying my girl wants a threesome with me & him. If he's unsure, I ask when was the last time he'd had anal with a girl, in case that helps him come around.
I get my GF to assume control, telling us to strip while filming us. That gives a neat way for me to watch it back again later, seeing his briefs, his cock springing to life, his bell-end and balls. She might get us to stand with our cockheads close together so she can alternate between sucking us off, but also so she can give me the thrill of rubbing the head of his cock against mine.
When it's fuck time, she goes on top of me with me in her vagina. She gets him to position his cock at her head end so she can suck it, but she also guides it as close over my face as possible (for my benefit too). She eventually lets him position to doggystyle her, but she grabs his cock, telling him to start in her pussy, squeezing his cock in alongside mine. Of course two large erections in her pussy is a real experience for her, but at the same time I get the length of my cock fucked by the length of my mate's cock, all under the guise of a hetero DP fuck. I especially love the feeling of the rim of his cockhead passing across the rim of mine, and also how his bloated balls impact with mine, even if at times uncomfortable.
She tells me to lube her asshole, so I reach for the lube and apply it to her ass. She tells me to put some all over his cock, of course giving me the opportunity to further experience my mate's penis, and gets me to guide him into her anus while I stay in her pussy. This is of course super-sexy for all three of us, and it feels great to feel my mate's cock pumping away next door right alongside. I see right into his face as it contorts through fucking a slim sexy brunette in the arse. Depending on how the guy has reacted, she might instruct we two men to snog.
For one of my friends he seemed completely into the whole thing, letting me work a couple of lubed fingers into his ass while he kept butt-fucking my girl. That led to me doing some butt-fucking of my own. Once inside him I just had to hold still, letting the rise & fall of his ass fuck my cock as he kept plowing into my GF.
So at least that friend now knows I'm beyond just hetero, but I still prefer us to think of our encounter as a DP threesome between me, my GF, & a friend who my GF had chosen to join us.