I have a GF who has a VERY strong fantasy about watching 2 guys have sex.
Once I told her I had sucked another guy's cock, she went wild! I had to share every detail of each encounter, and answer any questions she had.
Naturally, we began fantasizing about arranging such scenarios, and she couldn't wait until our first date because she wanted to fuck my ass with her dildo.
She was also fucking this other guy; they were casual friends ("fuck buddies"), and we all knew each other from school, but I wasn't 'friends' with him. He wasn't an enemy or anything, but we never hung out or ran around together.
Anyway, recognizing an opportunity, she began setting both of us up (me moreso than him). She hatched a plan to have a 3-way with him and us, and was telling him I was very receptive to the idea, and that I wanted to suck his cock, and would let him fuck me. This was all true, but I had admitted this to her not knowing she was sharing that info with that guy.
When she was with him, she would ask if he had any interest in general, and would he want to have sex with me specifically. Of course, when would talk or be together, she would do the same for me. She finally told him if he would get behind me and stick his cock against my ass that I wouldn't stop him, and they agreed it was a plan.
Long story short, circumstances failed at the last minute, so the 3 way never happened.
In any case, my point to all this is when we are fantasizing about her watching me have bi sex, the talk gets very hot and dirty, and she makes me admit I like cock, I want to suck and swallow, and take one in my ass.
When we are together, she will fuck me with her dildos almost every night. I have also had to suck it, both before she fucks me, and suck and lick it clean after she has. And she makes me admit I would still submit to her friend, and that I still want to suck his cock. In many different ways!