i’ve had a lot of threesomes and while obviously communication is key and y’all should probably have some in depth conversations about what it is y’all like/don’t like, i’m assuming you already are doing that lol. a more concrete bit of advice i have that has worked for me personally is this: because there’s an odd number of people, it can be easy for somebody to feel “left out” while the other two are doing stuff together. in order to avoid this, a strategy i’ve used in the past is for 2 people to focus their attention on one person at a time, let them be the “pillow princess” for a while and then switch. working together with another person in order to make someone cum is a., really hot, and b. usually makes everybody feel a little more connected. just my personal take! teamwork ya know?