This isn't the first time Ramona and Missy have hung out — she also invited her to her housewarming party in Season 9. And you may recall that Missy and Tom used to date before he and Luann became exclusive. Tom also had that infamous hot mic moment with Missy; check that clip out above.
And as for how Luann feels about this friendship? We have a feeling the cabaret star is unbothered; she actually "liked" the Instagram post!
For another blast from the past, check out this vintage RHONY moment featuring Tom, below.