When stars merge or join is it because they are in love? Is that called binary fusion. Is it for eternity?

The old professor says: In binary systems where the mass of one star is much greater than the mass of its companion, the more massive star will draw off material from the less massive one. The larger mass star thus gets more massive and can eventually pull in its companion to form one star. It can be considered a fusion by accretion. The larger mass star "loves" the smaller mass stars stuff and like the black widow spider, loves it to death. Unfortunately for the larger mass star, this gain in mass (like a heavy person) shortens its life span. So, you see...its not for "eternity".By the way, fusion in the cores of stars requires more than two hydrogens to form one helium...the process is known as the "triple alpha" process and it is composed of several steps. It releases energy in the form of gamma radiation...not heat and light directly.