And when was the last time someone went into someone else's house.

I don't think Phil's been in the Masood's house since 2007, but he did go in there when Alfie lived there with Nana.

Who else?

Johnny hasn't been in The Beales or The Mitchells I don't think ....yet

Kush hasn't been in anyones, neither has Donna.

Johnny went to the beales when he and whitney comforted lucy after danny got dumped.
New shabnam I don't recall vowing anyone but Denise and not even going into the vic
Pam hasn't been to ians
Cora hasn't been to masoods

Shabnam went into The Vic when she first arrived to give some already made meals to Bianca because of Carol's diagnosis.

Has Phil ever been in the Slaters? and has Kat ever been in Phils?

I can't think of specific scenes but probably. When Kat and Alfie first returned and leased the Vic I suspect Phil would have come round to bully the rent out of Alfie or something. Plus Gary used to live there whilst Phil's employee, he probably came round at least once to bully him into work.

Similarly, when Phil threw Kat and Alfie out of the Vic, Kat probably had at least one scene in the Mitchell house begging for Almighty Philths forgiveness.

Then there's all the many implausible Hen or Stag parties that must have taken place at either property over the years.

I remember now, one time Kat was in Phil's kitchen begging him not to be evicted or summat like that.