Is having sex after producing children a sin?

[An online spiritual discussion was conducted on May 15, 2021, in which several devotees participated. Devotees’ questions answered by Swāmi are given below.]

[Śrī Anil Antony asked: Pādanamaskāraṃ Swāmiji! You mentioned that expelling the sperm by hand is a sin. In that case, can we say that having sex after producing children is also a sin?]

Swāmi replied: Sex, which is legitimate is not a sin even after producing children. Legitimate means sex with wife (Dharmāviruddhaḥ… – Gītā).