Thanos had way more children than two
In the Marvel Cinematic Universe, Thanos’s apparent affection for his daughter Gamora is one of the main aspects that makes him a questionably sympathetic person. After he murders her to get the Soul Stone, it becomes very evident how much she means to him and how much his heart is broken by the thought of betraying her.
Unlike his adopted assassin daughters from the MCU, Thanos has a large number of biological children in the books, much outnumbering those he had with Nebula and Gamora. The most famous of Thanos’ many children is Thane, the secret son of the Mad Titan and an Inhuman. Thane may have a dark past, but Thanos and the rest of his progeny have an even more heinous one, as recounted in the 2013 miniseries “Thanos Rising” by Jason Aaron and illustrator Simone Bianchi.
In an effort to change his violent ways, Thanos joins a pirate ship as the ship’s navigator. Thanos meets and sleeps with ladies from several planets in his official position. These ladies often raise families. Thanos initially does not hurt any of his interstellar offspring. The second time around, though, Thanos falls hopelessly in love with Death and makes a solemn pledge to prove his devotion to her by locating all of his offspring and killing their mothers.

