If someone had a baby boy and the bris was pushed off until what came out to be the day of the Pidyon HaBen. Can the 2 seudas, one for the Bris and the other for the Pidyon HaBen be made together as one seudas mitzvah? Or is this a problem of being "marvin simcha b'simcha (mixing together 2 separate simchas.) Are there any sources on this?
Sefer Yismach Lev Volume 4 / Page 92 brings from Tosfos Moed Kattan 8b - Mipnei Bitul Pirya V'Rivya that one may make a Bris on Chol HaMoed as it is not considered a Simcha as there is pain for the circumcised child.
He says that Tosfos finishes and says that there is no issue of mixing Simchas only by weddings.