Is it permissible for my husband to masturbate over me, without me actually touching him and swallow his sperm? Is it also permissible for my husband to place his erect penis between my breasts, to hold them and masturbate?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Masturbating through wife's hand or her body is permissible, since Allah allows a husband and wife to enjoy with each other as they wish provided one should avoid having sex in her anus or in vagina during her menses.
As for swallowing a husband's sperm, it is contradictory to sound nature and good manners.
Moreover, few scholars believe that sperm is impure; based on this opinion it is unlawful to swallow it. However, this opinion regarding the impurity of sperm is weak.
Allah knows best.