Am I the only one

Hi everyone I'm new to this app, I want to know what would you do or have you been through this ir something similar and can share any advice that would be helpful.

So me and my boyfriend of 10 years want to try something new in the bedroom, we want to experience a 3sum with another female, we have so many fantasies and want to try them out since we both are so comfortable with each other and have been together for such a long time.

The only worry that may stop me fulfilling my fantasies is that I have tubular breasts and sometimes I don't feel sexy or feel like a woman as they don't look anything like normal breasts.

I'm worried incase the other female wants to run a mile as soon as she sees them which might make it awkward or she might have perfect breasts and my boyfriend sees mines next to hers and likes hers more in the moment and then I start to feel awkard as he has only saw mines for the past 10 years.

Anyone know what I should do or have been through something similar? Xx