I understand that the term “partner” has a wide meaning. This a Catholic board and as an old lady, I am going to answer as if you said “my spouse”.
Our spouses help us get to heaven. As long as sexual acts between validly married people respect the dignity of the other spouse and are ordered toward procreation there is no sin. If the married couple wishes to have sex many times every day, see the two conditions above.
Now, if the act is done in a disordered manner or violates the dignity of the other, then, time for some prayer and fasting.